1. CELL 당 제원
- 3.3V/10AH
- 310g, 3.8Cm ~ 14.68Cm
- 직렬연결 : 36V/10Ah (360W)
- Continuous discharge rate : 5C
- Max discharge rate : 15C (10~15초 동안 순간방전율)
- BMS에서 충전회수 고려하여 Continuous 방전율 4C로 유지 (4C면 1.5Kw 모터구동가능)
- 가격은 40~50만원대
- 장점 : Bolt로 조이는 방식으로 연결용이
2. 일반적인 LIFEPO4 제원
- 충방전 1000회 수명
- 1C로 충방전해야 수명이 오래감
- 10C로 충전하는데 5분 소요(3CELL2S병렬)
3. 기타사항
- 36V/15AH는 보통 1C충방전을 할경우 540W 모터 가동가능 1.5C로 할경우 700W의 모터도 가동가능
- 1차적으로 과충전,방전등은 BMS가 방지하고, 2차적으로는 CONTROLLER가 방지한다.
과충전방지로 40A 퓨즈를 달기도하나. 온도센서를 달아서 방지하기도 한다.
-리튬이온등은 3.7V가 표준인데, LIFEPO4는 3.3V가 표준이다.따라서 36V를 위해서는 12개를
직렬로 연결해야한다. 나머지는 용량을 맞추기 위해 병렬로 연결하여야 한다.
36개를 사용하면 Primastic 1 CELL당 3.3V/5Ah이다
2009년 9월 29일 화요일
2009년 9월 25일 금요일
Re: Automatic Transmission?
Roy LeMeur
Fri, 06 Sep 2002 21:30:33 -0700
Eric Patchem wrote:
--------------------
I had recently inquired about directly coupling the motor to the axles using
a fixed gear ratio. I had asked this because my car has an automatic
transmission. I had read that an automatic transmission is less efficient
than a manual. Which would be less efficient, the automatic tranny or the
fixed gearbox (or chain)? I have a 93 ford festiva which I want to convert.
A manual tranny probably wouldn't cost that much, but I am trying to do this
conversion with as little stress as possible. I have many ideas, but I would
like to bounce those ideas off anyone who will listen.
--------------------
As a start here are a couple of answers from the FAQs at evparts.com:
============
Can I build an EV with an automatic transmission?
An automatic transmission can be used in an EV conversion, but the
modifications required to it are likely beyond the scope of most
enthusiasts. The torque curve of an EV motor/controller combination is not
the same as the ICE it replaces, therefore the shifting points (what
speed/RPM the transmission shifts gears) will have to be changed. In older
transmissions this can be accomplished by modifying the valve body within
the transmission (the assembly that routes the fluid under pressure,
activating the bands), or in the case of more modern transmissions,
modifying the computer code that controls the electronic servos inside the
transmission. Since the benefits are rather minor, the work required
complex, and there is a decrease in overall efficiency compared to a
standard transmission, you don't see very many automatic transmission EV's.
Stick to donor chassis that came with a manual transmission from the factory
and it will save you a lot of time, trouble and money in the long run.
Mark Brueggemann 16JAN01
[EMAIL PROTECTED]
Good arguments for the convenience of automatics have also been posted on
the EV discussion list. An alternative to modifying valves and logic module
code is just to shift into "L2" or "L1" instead of "D". With an electric
motor, you may not even need to shift into "D" for the high gear. I would
tend to keep the torque converter, install an external fluid pump, and do
this. It would let me have more flexibility in choosing a donor vehicle.
Then again, manuals seem to be a whole lot easier to work with. As in many
other aspects of converting a vehicle, it comes down to what you want out of
the vehicle. For many, the convenience is worth the slight decrease in
efficiency. For others, premium efficiency and control is a requirement, and
this requires a manual.
David Brandt
5/21/01
[EMAIL PROTECTED]
====================
There are a couple (or more) other ways it can be done....
1 - Provide pressure with an "always on" dedicated pump motor, no torque
converter, always in gear, manual valve body.
2 - This is the setup in the Maniac Mazda: (GM powerglide), no motor to run
pump, no torque converter, manual valve body. Pump and input shaft coupled
directly to propulsion motors, (2 ADC 9" coupled end to end). Spin the drive
motors, pressure builds,(quickly), clutches engage, car is propelled
forward. (this feature contributes to the _maniac_ part, it makes for great
launches)
This setup may not be optimum for long clutch and band life :^D.
Though there are probably more aftermarket drag racing upgrades for the
powerglide than most any other automatic, it has been a workhorse in drag
racing for many years.
EV FAQ at evparts.com:
http://www.evparts.com/faq/index.php
More info on the Maniac Mazda:
http://www.evparts.com/about/index.php?show=mazda.ihtml
See GIF of Maniac Mazda make front suspension breakin' wheelie on this page:
http://www.dcpowersystems.com
Also, I believe that one or more of our controller gurus have also used the
auto trans setup as a test bed/science experiment.
Damon? Otmar?
Fri, 06 Sep 2002 21:30:33 -0700
Eric Patchem wrote:
--------------------
I had recently inquired about directly coupling the motor to the axles using
a fixed gear ratio. I had asked this because my car has an automatic
transmission. I had read that an automatic transmission is less efficient
than a manual. Which would be less efficient, the automatic tranny or the
fixed gearbox (or chain)? I have a 93 ford festiva which I want to convert.
A manual tranny probably wouldn't cost that much, but I am trying to do this
conversion with as little stress as possible. I have many ideas, but I would
like to bounce those ideas off anyone who will listen.
--------------------
As a start here are a couple of answers from the FAQs at evparts.com:
============
Can I build an EV with an automatic transmission?
An automatic transmission can be used in an EV conversion, but the
modifications required to it are likely beyond the scope of most
enthusiasts. The torque curve of an EV motor/controller combination is not
the same as the ICE it replaces, therefore the shifting points (what
speed/RPM the transmission shifts gears) will have to be changed. In older
transmissions this can be accomplished by modifying the valve body within
the transmission (the assembly that routes the fluid under pressure,
activating the bands), or in the case of more modern transmissions,
modifying the computer code that controls the electronic servos inside the
transmission. Since the benefits are rather minor, the work required
complex, and there is a decrease in overall efficiency compared to a
standard transmission, you don't see very many automatic transmission EV's.
Stick to donor chassis that came with a manual transmission from the factory
and it will save you a lot of time, trouble and money in the long run.
Mark Brueggemann 16JAN01
[EMAIL PROTECTED]
Good arguments for the convenience of automatics have also been posted on
the EV discussion list. An alternative to modifying valves and logic module
code is just to shift into "L2" or "L1" instead of "D". With an electric
motor, you may not even need to shift into "D" for the high gear. I would
tend to keep the torque converter, install an external fluid pump, and do
this. It would let me have more flexibility in choosing a donor vehicle.
Then again, manuals seem to be a whole lot easier to work with. As in many
other aspects of converting a vehicle, it comes down to what you want out of
the vehicle. For many, the convenience is worth the slight decrease in
efficiency. For others, premium efficiency and control is a requirement, and
this requires a manual.
David Brandt
5/21/01
[EMAIL PROTECTED]
====================
There are a couple (or more) other ways it can be done....
1 - Provide pressure with an "always on" dedicated pump motor, no torque
converter, always in gear, manual valve body.
2 - This is the setup in the Maniac Mazda: (GM powerglide), no motor to run
pump, no torque converter, manual valve body. Pump and input shaft coupled
directly to propulsion motors, (2 ADC 9" coupled end to end). Spin the drive
motors, pressure builds,(quickly), clutches engage, car is propelled
forward. (this feature contributes to the _maniac_ part, it makes for great
launches)
This setup may not be optimum for long clutch and band life :^D.
Though there are probably more aftermarket drag racing upgrades for the
powerglide than most any other automatic, it has been a workhorse in drag
racing for many years.
EV FAQ at evparts.com:
http://www.evparts.com/faq/index.php
More info on the Maniac Mazda:
http://www.evparts.com/about/index.php?show=mazda.ihtml
See GIF of Maniac Mazda make front suspension breakin' wheelie on this page:
http://www.dcpowersystems.com
Also, I believe that one or more of our controller gurus have also used the
auto trans setup as a test bed/science experiment.
Damon? Otmar?
AUTO TRANSMISSION에 LOCK UP이 있는지 확인
Re: Automatic Transmission?
Lee Hart
Fri, 06 Sep 2002 12:42:49 -0700
Patchem, Eric EM2 wrote:
> I had read that an automatic transmission is less efficient than a
> manual.
The efficiency of a manual and automatic transmission are essentially
the same; both well above 90%. The problem with the automatic is
entirely in the torque converter, which goes between the engine and
transmission. It is basically a big slipping clutch.
Some newer cars have torque converters that "lock up" under certain
conditions or above a certain speed. If your Fiesta has such a locking
torque converter, you can probably use the automatic as-is with no loss
of efficiency.
If you do NOT have a locking torque converter, then you're going to
suffer a 10% or so loss in range due to the slipping torque converter.
Automatic transmissions need oil pressure to shift. The pressure comes
from an oil pump on the front of the transmission that is turned by the
torque converter. So you have to "idle" the electric motor when the car
is stopped to maintain oil pressure for the transmission to work.
Or, you can keep the automatic transmission but leave out the torque
converter. This will require some machinist work to connect the motor,
and seal up the oil flow that normally goes between transmission and
torque converter. You will also want to add an external oil pump or
motor to operate the transmission's internal oil pump to maintain
operation.
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
Lee Hart
Fri, 06 Sep 2002 12:42:49 -0700
Patchem, Eric EM2 wrote:
> I had read that an automatic transmission is less efficient than a
> manual.
The efficiency of a manual and automatic transmission are essentially
the same; both well above 90%. The problem with the automatic is
entirely in the torque converter, which goes between the engine and
transmission. It is basically a big slipping clutch.
Some newer cars have torque converters that "lock up" under certain
conditions or above a certain speed. If your Fiesta has such a locking
torque converter, you can probably use the automatic as-is with no loss
of efficiency.
If you do NOT have a locking torque converter, then you're going to
suffer a 10% or so loss in range due to the slipping torque converter.
Automatic transmissions need oil pressure to shift. The pressure comes
from an oil pump on the front of the transmission that is turned by the
torque converter. So you have to "idle" the electric motor when the car
is stopped to maintain oil pressure for the transmission to work.
Or, you can keep the automatic transmission but leave out the torque
converter. This will require some machinist work to connect the motor,
and seal up the oil flow that normally goes between transmission and
torque converter. You will also want to add an external oil pump or
motor to operate the transmission's internal oil pump to maintain
operation.
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
AUTO TRANSMISSION 구조
http://www.centraltransmission.com/What_The_Heck_Is_A_Transmis.html
What is a transmission?
The modern automatic transmission is by far, the most complicated mechanical component in today's automobile. Automatic transmissions contain mechanical systems, hydraulic systems, electrical systems and computer controls, all working together in perfect harmony which goes virtually unnoticed until there is a problem. This article will help you understand the concepts behind what goes on inside these technological marvels and what goes into repairing them when they fail.
The transmission is a device that is connected to the back of the engine and sends the power from the engine to the drive wheels. An automobile engine runs at its best at a certain RPM (Revolutions Per Minute) range and it is the transmission's job to make sure that the power is delivered to the wheels while keeping the engine within that range. It does this through various gear combinations. In first gear, the engine turns much faster in relation to the drive wheels, while in high gear the engine is loafing even though the car may be going in excess of 70 MPH. In addition to the various forward gears, a transmission also has a neutral position that disconnects the engine from the drive wheels, and reverse, which causes the drive wheels to turn in the opposite direction allowing you to back up. Finally, there is the Park position. In this position, a latch mechanism (not unlike a deadbolt lock on a door) is inserted into a slot in the output shaft to lock the drive wheels and keep them from turning, thereby preventing the vehicle from rolling.
There are two basic types of automatic transmissions based on whether the vehicle is rear wheel drive or front wheel drive. On a rear wheel drive car, the transmission is usually mounted to the back of the engine and is located under the hump in the center of the floorboard alongside the gas pedal position. A drive shaft connects the rear of the transmission to the final drive that is located in the rear axle and is used to send power to the rear wheels. Power flow on this system is simple and straight forward going from the engine, through the torque converter, then through the transmission and drive shaft until it reaches the final drive where it is split and sent to the two rear wheels.
On a front wheel drive car, the transmission is usually combined with the final drive to form what is called a transaxle. The engine on a front wheel drive car is usually mounted sideways in the car with the transaxle tucked under it on the side of the engine facing the rear of the car. Front axles are connected directly to the transaxle and provide power to the front wheels. In this example, power flows from the engine, through the torque converter to a large chain that sends the power through a 180-degree turn to the transmission that is along side the engine. From there, the power is routed through the transmission to the final drive where it is split and sent to the two front wheels through the drive axles. There are a number of other arrangements including front drive vehicles where the engine is mounted front to back instead of sideways and there are other systems that drive all four wheels but the two systems described here are by far the most popular. A much less popular rear drive arrangement has the transmission mounted directly to the final drive at the rear and is connected by a drive shaft to the torque converter which is still mounted on the engine. This system is found on the new Corvette and is used in order to balance the weight evenly between the front and rear wheels for improved performance and handling.
So Many Parts...
The main components that make up an automatic transmission include:· Planetary Gear Sets that are the mechanical systems that provide the various forward gear ratios as well as reverse. · The Hydraulic System which uses a special transmission fluid sent under pressure by an Oil Pump through the Valve Body to control the Clutches and the Bands in order to control the planetary gear sets. · Seals and Gaskets are used to keep the oil where it is supposed to be and prevent it from leaking out. · The Torque Converter that acts like a clutch to allow the vehicle to come to a stop in gear while the engine is still running. · The Governor and the Modulator or Throttle Cable that monitor speed and throttle position in order to determine when to shift. · On newer vehicles, shift points are controlled by Computer which directs electrical solenoids to shift oil flow to the appropriate component at the right instant.
Planetary Gear Sets
Automatic transmissions contain many gears in various combinations. In a manual transmission, gears slide along shafts as you move the shift lever from one position to another, engaging various sized gears as required in order to provide the correct gear ratio. In an automatic transmission, however, the gears are never physically moved and are always engaged to the same gears. This is accomplished through the use of planetary gear sets.
The basic planetary gear set consists of a sun gear, a ring gear and two or more planet gears, all remaining in constant mesh. The planet gears are connected to each other through a common carrier that allows the gears to spin on shafts called "pinions" which are attached to the carrier.
One example of a way that this system can be used is by connecting the ring gear to the input shaft coming from the engine, connecting the planet carrier to the output shaft, and locking the sun gear so that it can't move. In this scenario, when we turn the ring gear, the planets will "walk" along the sun gear (which is held stationary) causing the planet carrier to turn the output shaft in the same direction as the input shaft but at a slower speed causing gear reduction (similar to a car in first gear).
If we unlock the sun gear and lock any two elements together, this will cause all three elements to turn at the same speed so that the output shaft will turn at the same rate of speed as the input shaft. This is like a car that is in third or high gear. Another way that we can use a Planetary gear set is by locking the planet carrier from moving, then applying power to the ring gear which will cause the sun gear to turn in the opposite direction giving us reverse gear.
The illustration above shows how the simple system described above would look in an actual transmission. The input shaft is connected to the ring gear (Blue), The Output shaft is connected to the planet carrier (Green) which is also connected to a "Multi-disk" clutch pack. The sun gear is connected to a drum (yellow) that is also connected to the other half of the clutch pack. Surrounding the outside of the drum is a band (red) that can be tightened around the drum when required to prevent the drum with the attached sun gear from turning.
The clutch pack is used, in this instance, to lock the planet carrier with the sun gear forcing both to turn at the same speed. If both the clutch pack and the band were released, the system would be in neutral.
Turning the input shaft would turn the planet gears against the sun gear, but since nothing is holding the sun gear, it will just spin free and have no effect on the output shaft.
To place the unit in first gear, the band is applied to hold the sun gear from moving. To shift from first to high gear, the band is released and the clutch is applied causing the output shaft to turn at the same speed as the input shaft.
Many more combinations are possible using two or more planetary sets connected in various ways to provide the different forward speeds and reverse that are found in modern automatic transmissions.
Some of the clever gear arrangements found in four and now, five, six and even seven-speed automatics are complex enough to make a technically astute lay person's head spin trying to understand the flow of power through the transmission as it shifts from first gear through top gear while the vehicle accelerates to highway speed. On newer vehicles, the vehicle's computer monitors and controls these shifts so that they are almost imperceptible.
Clutch Packs
A clutch pack consists of alternating disks that fit inside a clutch drum. Half of the disks are steel and have splines that fit into groves on the inside of the drum. The other half have a friction material bonded to their surface and have splines on the inside edge that fit groves on the outer surface of the adjoining hub. There is a piston inside the drum that is activated by oil pressure at the appropriate time to squeeze the clutch pack together so that the two components become locked and turn as one.
One-Way Clutch
A one-way clutch (also known as a "sprag" clutch) is a device that will allow a component such as ring gear to turn freely in one direction but not in the other. This effect is just like that of a bicycle, where the pedals will turn the wheel when pedaling forward, but will spin free when pedaling backward. A common place where a one-way clutch is used is in first gear when the shifter is in the drive position. When you begin to accelerate from a stop, the transmission starts out in first gear. But have you ever noticed what happens if you release the gas while it is still in first gear? The vehicle continues to coast as if you were in neutral. Now, shift into Low gear instead of Drive. When you let go of the gas in this case, you will feel the engine slow you down just like a standard shift car. The reason for this is that in Drive, a one-way clutch is used whereas in Low, a clutch pack or a band is used.
Bands
A band is a steel strap with friction material bonded to the inside surface. One end of the band is anchored against the transmission case while the other end is connected to a servo. At the appropriate time hydraulic oil is sent to the servo under pressure to tighten the band around the drum to stop the drum from turning.
Torque Converter
On automatic transmissions, the torque converter takes the place of the clutch found on standard shift vehicles. It is there to allow the engine to continue running when the vehicle comes to a stop. The principle behind a torque converter is like taking a fan that is plugged into the wall and blowing air into another fan that is unplugged. If you grab the blade on the unplugged fan, you are able to hold it from turning but as soon as you let go, it will begin to speed up until it comes close to the speed of the powered fan. The difference with a torque converter is that instead of using air, it uses oil or transmission fluid, to be more precise.
A torque converter is a large doughnut shaped device (10" to 15" in diameter) that is mounted between the engine and the transmission. It consists of three internal elements that work together to transmit power to the transmission. The three elements of the torque converter are the Pump, the Turbine, and the Stator.
The pump is mounted directly to the converter housing that in turn is bolted directly to the engine's crankshaft and turns at engine speed. The turbine is inside the housing and is connected directly to the input shaft of the transmission providing power to move the vehicle.
The stator is mounted to a one-way clutch so that it can spin freely in one direction but not in the other. Each of the three elements have fins mounted in them to precisely direct the flow of oil through the converter with the engine running, transmission fluid is pulled into the pump section and is pushed outward by centrifugal force until it reaches the turbine section that starts it turning.
The fluid continues in a circular motion back towards the center of the turbine where it enters the stator. If the turbine is moving considerably slower than the pump, the fluid will make contact with the front of the stator fins that push the stator into the one-way clutch and prevent it from turning. With the stator stopped, the fluid is directed by the stator fins to re-enter the pump at a "helping" angle providing a torque increase. As the speed of the turbine catches up with the pump, the fluid starts hitting the stator blades on the backside causing the stator to turn in the same direction as the pump and turbine. As the speed increases, all three elements begin to turn at approximately the same speed.
Since the '80s, in order to improve fuel economy, torque converters have been equipped with a lockup clutch (not shown) that locks the turbine to the pump as the vehicle speed reaches approximately 45 - 50 MPH. This lockup is controlled by computer and usually won't engage unless the transmission is in 3rd or 4th gear.
Hydraulic System
The Hydraulic system is a complex maze of passages and tubes that sends transmission fluid under pressure to all parts of the transmission and torque converter.
The diagram above is a simple one from a 3-speed automatic from the '60s. The newer systems are much more complex and are combined with computerized electrical components.
Transmission fluid serves a number of purposes including: shift control, general lubrication and transmission cooling. Unlike the engine, which uses oil primarily for lubrication, every aspect of a transmission's functions is dependent on a constant supply of fluid under pressure. This is not unlike the human circulatory system (the fluid is even red) where even a few minutes of operation when there is a lack of pressure can be harmful or even fatal to the life of the transmission.
In order to keep the transmission at normal operating temperature, a portion of the fluid is sent through one of two steel tubes to a special chamber that is submerged in anti-freeze in the radiator. Fluid passing through this chamber is cooled and then returned to the transmission through the other steel tube.
A typical transmission has an average of ten quarts of fluid between the transmission, torque converter, and cooler tank. In fact, most of the components of a transmission are constantly submerged in fluid including the clutch packs and bands. The friction surfaces on these parts are designed to operate properly only when they are submerged in oil.
Oil Pump
The transmission oil pump (not to be confused with the pump element inside the torque converter) is responsible for producing all the oil pressure that is required in the transmission. The oil pump is mounted to the front of the transmission case and is directly connected to a flange on the torque converter housing.
Since the torque converter housing is directly connected to the engine crankshaft, the pump will produce pressure whenever the engine is running as long as there is a sufficient amount of transmission fluid available. The oil enters the pump through a filter that is located at the bottom of the transmission oil pan and travels up a pickup tube directly to the oil pump. The oil is then sent, under pressure to the pressure regulator, the valve body and the rest of the components, as required.
Valve Body
The valve body is the control center of the automatic transmission. It contains a maze of channels and passages that direct hydraulic fluid to the numerous valves that then activate the appropriate clutch pack or band servo to smoothly shift to the appropriate gear for each driving situation.
Each of the many valves in the valve body has a specific purpose and is named for that function. For example the 2-3-shift valve activates the 2nd gear to 3rd gear up-shift or the 3-2 shift-timing valve that determines when a downshift should occur.The most important valve, and the one that you have direct control over is the manual valve. The manual valve is directly connected to the gearshift handle and covers and uncovers various passages depending on what position the gear shift is placed in.
When you place the gearshift in Drive, for instance, the manual valve directs fluid to the clutch pack(s) that activates 1st gear. it also sets up to monitor vehicle speed and throttle position so that it can determine the optimal time and the force for the 1 - 2 shift. On computer controlled transmissions, you will also have electrical solenoids that are mounted in the valve body to direct fluid to the appropriate clutch packs or bands under computer control to more precisely control shift points.
Computer Controls
The computer uses sensors on the engine and transmission to detect such things as throttle position, vehicle speed, engine speed, engine load, brake pedal position, etc. to control exact shift points as well as how soft or firm the shift should be. Once the computer receives this information, it then sends signals to a solenoid pack inside the transmission. The solenoid pack contains several electrically controlled solenoids that redirect the fluid to the appropriate clutch pack or servo in order to control shifting. Computerized transmissions even learn your driving style and constantly adapt to it so that every shift is timed precisely when you would need it.
Because of computer controls, sports models are coming out with the ability to take manual control of the transmission as though it were a stick shift, allowing the driver to select gears manually. This is accomplished on some cars by passing the shift lever through a special gate, then tapping it in one direction or the other in order to up-shift or downshift at will. The computer monitors this activity to make sure that the driver does not select a gear that could over speed the engine and damage it.
Another advantage to these "smart" transmissions is that they have a self-diagnostic mode that can detect a problem early on and warn you with an indicator light on the dash. A technician can then plug test equipment in and retrieve a list of trouble codes that will help pinpoint where the problem is.
Governor, Vacuum Modulator & Throttle Cable
These three components are important in the non-computerized transmissions. They provide the inputs that tell the transmission when to shift. The Governor is connected to the output shaft and regulates hydraulic pressure based on vehicle speed. It accomplishes this using centrifugal force to spin a pair of hinged weights against pull-back springs. As the weights pull further out against the springs, more oil pressure is allowed past the governor to act on the shift valves that are in the valve body which then signal the appropriate shifts.
Of course, vehicle speed is not the only thing that controls when a transmission should shift, the load that the engine is under is also important. The more load you place on the engine, the longer the transmission will hold a gear before shifting to the next one.
There are two types of devices that serve the purpose of monitoring the engine load: the Throttle Cable and the Vacuum Modulator. A transmission will use one or the other but generally not both of these devices. Each works in a different way to monitor engine load.
The Throttle Cable simply monitors the position of the gas pedal through a cable that runs from the gas pedal to the throttle valve in the valve body.
The Vacuum Modulator monitors engine vacuum by a rubber vacuum hose which is connected to the engine. Engine vacuum reacts very accurately to engine load with high vacuum produced when the engine is under light load and diminishing down to zero vacuum when the engine is under a heavy load. The modulator is attached to the outside of the transmission case and has a shaft that passes through the case and attaches to the throttle valve in the valve body. When an engine is under a light load or no load, high vacuum acts on the modulator that moves the throttle valve in one direction to allow the transmission to shift early and soft. As the engine load increases, vacuum is diminished which moves the valve in the other direction causing the transmission to shift later and more firmly.
Seals and Gaskets
An automatic transmission has many seals and gaskets to control the flow of hydraulic fluid and to keep it from leaking out. There are two main external seals: the front seal and the rear seal. The front seal seals the point where the torque converter mounts to the transmission case. This seal allows fluid to freely move from the converter to the transmission but keeps the fluid from leaking out. The rear seal keeps fluid from leaking past the output shaft.
A seal is usually made of rubber (similar to the rubber in a windshield wiper blade) and is used to keep oil from leaking past a moving part such as a spinning shaft. In some cases, the rubber is assisted by a spring that holds the rubber in close contact with the spinning shaft.
A gasket is a type of seal used to seal two stationary parts that are fastened together. Some common gasket materials are: paper, cork, rubber, silicone and soft metal.
Aside from the main seals, there are also a number of other seals and gaskets that vary from transmission to transmission. A common example is the rubber O-ring that seals the shaft for the shift control lever. This is the shaft that you move when you manipulate the gear shifter. Another example that is common to most transmissions is the oil pan gasket. In fact, seals are required anywhere that a device needs to pass through the transmission case with each one being a potential source for leaks.
What is a transmission?
The modern automatic transmission is by far, the most complicated mechanical component in today's automobile. Automatic transmissions contain mechanical systems, hydraulic systems, electrical systems and computer controls, all working together in perfect harmony which goes virtually unnoticed until there is a problem. This article will help you understand the concepts behind what goes on inside these technological marvels and what goes into repairing them when they fail.
The transmission is a device that is connected to the back of the engine and sends the power from the engine to the drive wheels. An automobile engine runs at its best at a certain RPM (Revolutions Per Minute) range and it is the transmission's job to make sure that the power is delivered to the wheels while keeping the engine within that range. It does this through various gear combinations. In first gear, the engine turns much faster in relation to the drive wheels, while in high gear the engine is loafing even though the car may be going in excess of 70 MPH. In addition to the various forward gears, a transmission also has a neutral position that disconnects the engine from the drive wheels, and reverse, which causes the drive wheels to turn in the opposite direction allowing you to back up. Finally, there is the Park position. In this position, a latch mechanism (not unlike a deadbolt lock on a door) is inserted into a slot in the output shaft to lock the drive wheels and keep them from turning, thereby preventing the vehicle from rolling.
There are two basic types of automatic transmissions based on whether the vehicle is rear wheel drive or front wheel drive. On a rear wheel drive car, the transmission is usually mounted to the back of the engine and is located under the hump in the center of the floorboard alongside the gas pedal position. A drive shaft connects the rear of the transmission to the final drive that is located in the rear axle and is used to send power to the rear wheels. Power flow on this system is simple and straight forward going from the engine, through the torque converter, then through the transmission and drive shaft until it reaches the final drive where it is split and sent to the two rear wheels.
On a front wheel drive car, the transmission is usually combined with the final drive to form what is called a transaxle. The engine on a front wheel drive car is usually mounted sideways in the car with the transaxle tucked under it on the side of the engine facing the rear of the car. Front axles are connected directly to the transaxle and provide power to the front wheels. In this example, power flows from the engine, through the torque converter to a large chain that sends the power through a 180-degree turn to the transmission that is along side the engine. From there, the power is routed through the transmission to the final drive where it is split and sent to the two front wheels through the drive axles. There are a number of other arrangements including front drive vehicles where the engine is mounted front to back instead of sideways and there are other systems that drive all four wheels but the two systems described here are by far the most popular. A much less popular rear drive arrangement has the transmission mounted directly to the final drive at the rear and is connected by a drive shaft to the torque converter which is still mounted on the engine. This system is found on the new Corvette and is used in order to balance the weight evenly between the front and rear wheels for improved performance and handling.
So Many Parts...
The main components that make up an automatic transmission include:· Planetary Gear Sets that are the mechanical systems that provide the various forward gear ratios as well as reverse. · The Hydraulic System which uses a special transmission fluid sent under pressure by an Oil Pump through the Valve Body to control the Clutches and the Bands in order to control the planetary gear sets. · Seals and Gaskets are used to keep the oil where it is supposed to be and prevent it from leaking out. · The Torque Converter that acts like a clutch to allow the vehicle to come to a stop in gear while the engine is still running. · The Governor and the Modulator or Throttle Cable that monitor speed and throttle position in order to determine when to shift. · On newer vehicles, shift points are controlled by Computer which directs electrical solenoids to shift oil flow to the appropriate component at the right instant.
Planetary Gear Sets
Automatic transmissions contain many gears in various combinations. In a manual transmission, gears slide along shafts as you move the shift lever from one position to another, engaging various sized gears as required in order to provide the correct gear ratio. In an automatic transmission, however, the gears are never physically moved and are always engaged to the same gears. This is accomplished through the use of planetary gear sets.
The basic planetary gear set consists of a sun gear, a ring gear and two or more planet gears, all remaining in constant mesh. The planet gears are connected to each other through a common carrier that allows the gears to spin on shafts called "pinions" which are attached to the carrier.
One example of a way that this system can be used is by connecting the ring gear to the input shaft coming from the engine, connecting the planet carrier to the output shaft, and locking the sun gear so that it can't move. In this scenario, when we turn the ring gear, the planets will "walk" along the sun gear (which is held stationary) causing the planet carrier to turn the output shaft in the same direction as the input shaft but at a slower speed causing gear reduction (similar to a car in first gear).
If we unlock the sun gear and lock any two elements together, this will cause all three elements to turn at the same speed so that the output shaft will turn at the same rate of speed as the input shaft. This is like a car that is in third or high gear. Another way that we can use a Planetary gear set is by locking the planet carrier from moving, then applying power to the ring gear which will cause the sun gear to turn in the opposite direction giving us reverse gear.
The illustration above shows how the simple system described above would look in an actual transmission. The input shaft is connected to the ring gear (Blue), The Output shaft is connected to the planet carrier (Green) which is also connected to a "Multi-disk" clutch pack. The sun gear is connected to a drum (yellow) that is also connected to the other half of the clutch pack. Surrounding the outside of the drum is a band (red) that can be tightened around the drum when required to prevent the drum with the attached sun gear from turning.
The clutch pack is used, in this instance, to lock the planet carrier with the sun gear forcing both to turn at the same speed. If both the clutch pack and the band were released, the system would be in neutral.
Turning the input shaft would turn the planet gears against the sun gear, but since nothing is holding the sun gear, it will just spin free and have no effect on the output shaft.
To place the unit in first gear, the band is applied to hold the sun gear from moving. To shift from first to high gear, the band is released and the clutch is applied causing the output shaft to turn at the same speed as the input shaft.
Many more combinations are possible using two or more planetary sets connected in various ways to provide the different forward speeds and reverse that are found in modern automatic transmissions.
Some of the clever gear arrangements found in four and now, five, six and even seven-speed automatics are complex enough to make a technically astute lay person's head spin trying to understand the flow of power through the transmission as it shifts from first gear through top gear while the vehicle accelerates to highway speed. On newer vehicles, the vehicle's computer monitors and controls these shifts so that they are almost imperceptible.
Clutch Packs
A clutch pack consists of alternating disks that fit inside a clutch drum. Half of the disks are steel and have splines that fit into groves on the inside of the drum. The other half have a friction material bonded to their surface and have splines on the inside edge that fit groves on the outer surface of the adjoining hub. There is a piston inside the drum that is activated by oil pressure at the appropriate time to squeeze the clutch pack together so that the two components become locked and turn as one.
One-Way Clutch
A one-way clutch (also known as a "sprag" clutch) is a device that will allow a component such as ring gear to turn freely in one direction but not in the other. This effect is just like that of a bicycle, where the pedals will turn the wheel when pedaling forward, but will spin free when pedaling backward. A common place where a one-way clutch is used is in first gear when the shifter is in the drive position. When you begin to accelerate from a stop, the transmission starts out in first gear. But have you ever noticed what happens if you release the gas while it is still in first gear? The vehicle continues to coast as if you were in neutral. Now, shift into Low gear instead of Drive. When you let go of the gas in this case, you will feel the engine slow you down just like a standard shift car. The reason for this is that in Drive, a one-way clutch is used whereas in Low, a clutch pack or a band is used.
Bands
A band is a steel strap with friction material bonded to the inside surface. One end of the band is anchored against the transmission case while the other end is connected to a servo. At the appropriate time hydraulic oil is sent to the servo under pressure to tighten the band around the drum to stop the drum from turning.
Torque Converter
On automatic transmissions, the torque converter takes the place of the clutch found on standard shift vehicles. It is there to allow the engine to continue running when the vehicle comes to a stop. The principle behind a torque converter is like taking a fan that is plugged into the wall and blowing air into another fan that is unplugged. If you grab the blade on the unplugged fan, you are able to hold it from turning but as soon as you let go, it will begin to speed up until it comes close to the speed of the powered fan. The difference with a torque converter is that instead of using air, it uses oil or transmission fluid, to be more precise.
A torque converter is a large doughnut shaped device (10" to 15" in diameter) that is mounted between the engine and the transmission. It consists of three internal elements that work together to transmit power to the transmission. The three elements of the torque converter are the Pump, the Turbine, and the Stator.
The pump is mounted directly to the converter housing that in turn is bolted directly to the engine's crankshaft and turns at engine speed. The turbine is inside the housing and is connected directly to the input shaft of the transmission providing power to move the vehicle.
The stator is mounted to a one-way clutch so that it can spin freely in one direction but not in the other. Each of the three elements have fins mounted in them to precisely direct the flow of oil through the converter with the engine running, transmission fluid is pulled into the pump section and is pushed outward by centrifugal force until it reaches the turbine section that starts it turning.
The fluid continues in a circular motion back towards the center of the turbine where it enters the stator. If the turbine is moving considerably slower than the pump, the fluid will make contact with the front of the stator fins that push the stator into the one-way clutch and prevent it from turning. With the stator stopped, the fluid is directed by the stator fins to re-enter the pump at a "helping" angle providing a torque increase. As the speed of the turbine catches up with the pump, the fluid starts hitting the stator blades on the backside causing the stator to turn in the same direction as the pump and turbine. As the speed increases, all three elements begin to turn at approximately the same speed.
Since the '80s, in order to improve fuel economy, torque converters have been equipped with a lockup clutch (not shown) that locks the turbine to the pump as the vehicle speed reaches approximately 45 - 50 MPH. This lockup is controlled by computer and usually won't engage unless the transmission is in 3rd or 4th gear.
Hydraulic System
The Hydraulic system is a complex maze of passages and tubes that sends transmission fluid under pressure to all parts of the transmission and torque converter.
The diagram above is a simple one from a 3-speed automatic from the '60s. The newer systems are much more complex and are combined with computerized electrical components.
Transmission fluid serves a number of purposes including: shift control, general lubrication and transmission cooling. Unlike the engine, which uses oil primarily for lubrication, every aspect of a transmission's functions is dependent on a constant supply of fluid under pressure. This is not unlike the human circulatory system (the fluid is even red) where even a few minutes of operation when there is a lack of pressure can be harmful or even fatal to the life of the transmission.
In order to keep the transmission at normal operating temperature, a portion of the fluid is sent through one of two steel tubes to a special chamber that is submerged in anti-freeze in the radiator. Fluid passing through this chamber is cooled and then returned to the transmission through the other steel tube.
A typical transmission has an average of ten quarts of fluid between the transmission, torque converter, and cooler tank. In fact, most of the components of a transmission are constantly submerged in fluid including the clutch packs and bands. The friction surfaces on these parts are designed to operate properly only when they are submerged in oil.
Oil Pump
The transmission oil pump (not to be confused with the pump element inside the torque converter) is responsible for producing all the oil pressure that is required in the transmission. The oil pump is mounted to the front of the transmission case and is directly connected to a flange on the torque converter housing.
Since the torque converter housing is directly connected to the engine crankshaft, the pump will produce pressure whenever the engine is running as long as there is a sufficient amount of transmission fluid available. The oil enters the pump through a filter that is located at the bottom of the transmission oil pan and travels up a pickup tube directly to the oil pump. The oil is then sent, under pressure to the pressure regulator, the valve body and the rest of the components, as required.
Valve Body
The valve body is the control center of the automatic transmission. It contains a maze of channels and passages that direct hydraulic fluid to the numerous valves that then activate the appropriate clutch pack or band servo to smoothly shift to the appropriate gear for each driving situation.
Each of the many valves in the valve body has a specific purpose and is named for that function. For example the 2-3-shift valve activates the 2nd gear to 3rd gear up-shift or the 3-2 shift-timing valve that determines when a downshift should occur.The most important valve, and the one that you have direct control over is the manual valve. The manual valve is directly connected to the gearshift handle and covers and uncovers various passages depending on what position the gear shift is placed in.
When you place the gearshift in Drive, for instance, the manual valve directs fluid to the clutch pack(s) that activates 1st gear. it also sets up to monitor vehicle speed and throttle position so that it can determine the optimal time and the force for the 1 - 2 shift. On computer controlled transmissions, you will also have electrical solenoids that are mounted in the valve body to direct fluid to the appropriate clutch packs or bands under computer control to more precisely control shift points.
Computer Controls
The computer uses sensors on the engine and transmission to detect such things as throttle position, vehicle speed, engine speed, engine load, brake pedal position, etc. to control exact shift points as well as how soft or firm the shift should be. Once the computer receives this information, it then sends signals to a solenoid pack inside the transmission. The solenoid pack contains several electrically controlled solenoids that redirect the fluid to the appropriate clutch pack or servo in order to control shifting. Computerized transmissions even learn your driving style and constantly adapt to it so that every shift is timed precisely when you would need it.
Because of computer controls, sports models are coming out with the ability to take manual control of the transmission as though it were a stick shift, allowing the driver to select gears manually. This is accomplished on some cars by passing the shift lever through a special gate, then tapping it in one direction or the other in order to up-shift or downshift at will. The computer monitors this activity to make sure that the driver does not select a gear that could over speed the engine and damage it.
Another advantage to these "smart" transmissions is that they have a self-diagnostic mode that can detect a problem early on and warn you with an indicator light on the dash. A technician can then plug test equipment in and retrieve a list of trouble codes that will help pinpoint where the problem is.
Governor, Vacuum Modulator & Throttle Cable
These three components are important in the non-computerized transmissions. They provide the inputs that tell the transmission when to shift. The Governor is connected to the output shaft and regulates hydraulic pressure based on vehicle speed. It accomplishes this using centrifugal force to spin a pair of hinged weights against pull-back springs. As the weights pull further out against the springs, more oil pressure is allowed past the governor to act on the shift valves that are in the valve body which then signal the appropriate shifts.
Of course, vehicle speed is not the only thing that controls when a transmission should shift, the load that the engine is under is also important. The more load you place on the engine, the longer the transmission will hold a gear before shifting to the next one.
There are two types of devices that serve the purpose of monitoring the engine load: the Throttle Cable and the Vacuum Modulator. A transmission will use one or the other but generally not both of these devices. Each works in a different way to monitor engine load.
The Throttle Cable simply monitors the position of the gas pedal through a cable that runs from the gas pedal to the throttle valve in the valve body.
The Vacuum Modulator monitors engine vacuum by a rubber vacuum hose which is connected to the engine. Engine vacuum reacts very accurately to engine load with high vacuum produced when the engine is under light load and diminishing down to zero vacuum when the engine is under a heavy load. The modulator is attached to the outside of the transmission case and has a shaft that passes through the case and attaches to the throttle valve in the valve body. When an engine is under a light load or no load, high vacuum acts on the modulator that moves the throttle valve in one direction to allow the transmission to shift early and soft. As the engine load increases, vacuum is diminished which moves the valve in the other direction causing the transmission to shift later and more firmly.
Seals and Gaskets
An automatic transmission has many seals and gaskets to control the flow of hydraulic fluid and to keep it from leaking out. There are two main external seals: the front seal and the rear seal. The front seal seals the point where the torque converter mounts to the transmission case. This seal allows fluid to freely move from the converter to the transmission but keeps the fluid from leaking out. The rear seal keeps fluid from leaking past the output shaft.
A seal is usually made of rubber (similar to the rubber in a windshield wiper blade) and is used to keep oil from leaking past a moving part such as a spinning shaft. In some cases, the rubber is assisted by a spring that holds the rubber in close contact with the spinning shaft.
A gasket is a type of seal used to seal two stationary parts that are fastened together. Some common gasket materials are: paper, cork, rubber, silicone and soft metal.
Aside from the main seals, there are also a number of other seals and gaskets that vary from transmission to transmission. A common example is the rubber O-ring that seals the shaft for the shift control lever. This is the shaft that you move when you manipulate the gear shifter. Another example that is common to most transmissions is the oil pan gasket. In fact, seals are required anywhere that a device needs to pass through the transmission case with each one being a potential source for leaks.
Convert Automatic Transmission to the EV
Re: Automatic Transmission?
--------------------------------------------------------------------------------
To: ev@listproc.sjsu.edu
Subject: Re: Automatic Transmission?
From: "Roy LeMeur"
Date: Fri, 06 Sep 2002 21:52:22 -0700
Reply-To: ev@listproc.sjsu.edu
Sender: owner-ev@listproc.sjsu.edu
--------------------------------------------------------------------------------
Eric Patchem wrote:
--------------------
I had recently inquired about directly coupling the motor to the axles using
a fixed gear ratio. I had asked this because my car has an automatic
transmission. I had read that an automatic transmission is less efficient
than a manual. Which would be less efficient, the automatic tranny or the
fixed gearbox (or chain)? I have a 93 ford festiva which I want to convert.
A manual tranny probably wouldn't cost that much, but I am trying to do this
conversion with as little stress as possible. I have many ideas, but I would
like to bounce those ideas off anyone who will listen.
--------------------
As a start here are a couple of answers from the FAQs at evparts.com:
============
Can I build an EV with an automatic transmission?
An automatic transmission can be used in an EV conversion, but the
modifications required to it are likely beyond the scope of most
enthusiasts. The torque curve of an EV motor/controller combination is not
the same as the ICE it replaces, therefore the shifting points (what
speed/RPM the transmission shifts gears) will have to be changed. In older
transmissions this can be accomplished by modifying the valve body within
the transmission (the assembly that routes the fluid under pressure,
activating the bands), or in the case of more modern transmissions,
modifying the computer code that controls the electronic servos inside the
transmission. Since the benefits are rather minor, the work required
complex, and there is a decrease in overall efficiency compared to a
standard transmission, you don't see very many automatic transmission EV's.
Stick to donor chassis that came with a manual transmission from the factory
and it will save you a lot of time, trouble and money in the long run.
Mark Brueggemann 16JAN01
markb@abq.com
Good arguments for the convenience of automatics have also been posted on
the EV discussion list. An alternative to modifying valves and logic module
code is just to shift into "L2" or "L1" instead of "D". With an electric
motor, you may not even need to shift into "D" for the high gear. I would
tend to keep the torque converter, install an external fluid pump, and do
this. It would let me have more flexibility in choosing a donor vehicle.
Then again, manuals seem to be a whole lot easier to work with. As in many
other aspects of converting a vehicle, it comes down to what you want out of
the vehicle. For many, the convenience is worth the slight decrease in
efficiency. For others, premium efficiency and control is a requirement, and
this requires a manual.
David Brandt
5/21/01
davidbr13@hotmail.com
====================
There are a couple (or more) other ways it can be done....
1 - Provide pressure with an "always on" dedicated pump motor, no torque
converter, always in gear, manual valve body.
2 - This is the setup in the Maniac Mazda: (GM powerglide), no motor to run
pump, no torque converter, manual valve body. Pump and input shaft coupled
directly to propulsion motors, (2 ADC 9" coupled end to end). Spin the drive
motors, pressure builds,(quickly), clutches engage, car is propelled
forward. (this feature contributes to the _maniac_ part, it makes for great
launches)
This setup may not be optimum for long clutch and band life :^D.
Though there are probably more aftermarket drag racing upgrades for the
powerglide than most any other automatic, it has been a workhorse in drag
racing for many years.
EV FAQ at evparts.com:
http://www.evparts.com/faq/index.php
More info on the Maniac Mazda:
http://www.evparts.com/about/index.php?show=mazda.ihtml
See GIF of Maniac Mazda make front suspension breakin' wheelie on this page:
http://www.dcpowersystems.com
Also, I believe that one or more of our controller gurus have also used the
auto trans setup as a test bed/science experiment.
Damon? Otmar?
--------------------------------------------------------------------------------
To: ev@listproc.sjsu.edu
Subject: Re: Automatic Transmission?
From: "Roy LeMeur"
Date: Fri, 06 Sep 2002 21:52:22 -0700
Reply-To: ev@listproc.sjsu.edu
Sender: owner-ev@listproc.sjsu.edu
--------------------------------------------------------------------------------
Eric Patchem wrote:
--------------------
I had recently inquired about directly coupling the motor to the axles using
a fixed gear ratio. I had asked this because my car has an automatic
transmission. I had read that an automatic transmission is less efficient
than a manual. Which would be less efficient, the automatic tranny or the
fixed gearbox (or chain)? I have a 93 ford festiva which I want to convert.
A manual tranny probably wouldn't cost that much, but I am trying to do this
conversion with as little stress as possible. I have many ideas, but I would
like to bounce those ideas off anyone who will listen.
--------------------
As a start here are a couple of answers from the FAQs at evparts.com:
============
Can I build an EV with an automatic transmission?
An automatic transmission can be used in an EV conversion, but the
modifications required to it are likely beyond the scope of most
enthusiasts. The torque curve of an EV motor/controller combination is not
the same as the ICE it replaces, therefore the shifting points (what
speed/RPM the transmission shifts gears) will have to be changed. In older
transmissions this can be accomplished by modifying the valve body within
the transmission (the assembly that routes the fluid under pressure,
activating the bands), or in the case of more modern transmissions,
modifying the computer code that controls the electronic servos inside the
transmission. Since the benefits are rather minor, the work required
complex, and there is a decrease in overall efficiency compared to a
standard transmission, you don't see very many automatic transmission EV's.
Stick to donor chassis that came with a manual transmission from the factory
and it will save you a lot of time, trouble and money in the long run.
Mark Brueggemann 16JAN01
markb@abq.com
Good arguments for the convenience of automatics have also been posted on
the EV discussion list. An alternative to modifying valves and logic module
code is just to shift into "L2" or "L1" instead of "D". With an electric
motor, you may not even need to shift into "D" for the high gear. I would
tend to keep the torque converter, install an external fluid pump, and do
this. It would let me have more flexibility in choosing a donor vehicle.
Then again, manuals seem to be a whole lot easier to work with. As in many
other aspects of converting a vehicle, it comes down to what you want out of
the vehicle. For many, the convenience is worth the slight decrease in
efficiency. For others, premium efficiency and control is a requirement, and
this requires a manual.
David Brandt
5/21/01
davidbr13@hotmail.com
====================
There are a couple (or more) other ways it can be done....
1 - Provide pressure with an "always on" dedicated pump motor, no torque
converter, always in gear, manual valve body.
2 - This is the setup in the Maniac Mazda: (GM powerglide), no motor to run
pump, no torque converter, manual valve body. Pump and input shaft coupled
directly to propulsion motors, (2 ADC 9" coupled end to end). Spin the drive
motors, pressure builds,(quickly), clutches engage, car is propelled
forward. (this feature contributes to the _maniac_ part, it makes for great
launches)
This setup may not be optimum for long clutch and band life :^D.
Though there are probably more aftermarket drag racing upgrades for the
powerglide than most any other automatic, it has been a workhorse in drag
racing for many years.
EV FAQ at evparts.com:
http://www.evparts.com/faq/index.php
More info on the Maniac Mazda:
http://www.evparts.com/about/index.php?show=mazda.ihtml
See GIF of Maniac Mazda make front suspension breakin' wheelie on this page:
http://www.dcpowersystems.com
Also, I believe that one or more of our controller gurus have also used the
auto trans setup as a test bed/science experiment.
Damon? Otmar?
전기자동차 newzealand 사례
http://www.kiwiev.com/19_2d_faq.html
The battery pack consists of twelve individual 12 volt deep-cycle Hella Endurant MDC24/85 batteries, rated at 85A/hrs and 515 CCA.
The 12 batteries will be connected in series to create 144 volts. Electric Vehicles must use deep-cycle batteries as they can handle a serious discharge much better than regular car or marine batteries. They're more expensive than marine or car batteries but last generally six times longer under standard use. While my battery pack is small with an unimpressive range, New Plymouth is a small town that's less than 10km (6 miles) across so range isn't important in our situation. The typical life expectancy of deep cycle lead acid batteries in an EV is generally about 3 years.
- The charging system I originally used consisted of 12 individual Calibre 3.5 Amp Australian made chargers - one for each battery. The reason for this setup was the cost. Overall this method cost me $708 NZ ($490 USD), as opposed to $1400 NZ for a single "pack" charger.
Now while this method was definitely cheap, it was slooooow. It ended up being cheaper to buy a $1400 Zivan 16 amp pack charger than replacing all the individual 12v chargers with 16 amp ones. So now that I've bought a 16 amp pack charger I'd have to say that I prefer it for speed and convenience.
The budget so far is made up of EV Conversion related purchases only. I have not included paint or basic tools as these are not applicable to every EV, and many tools I will use for other purposes. My own labour has been excluded also, unless I'm paying someone else for it of course!
The EV budget so far in New Zealand dollars is:
Advanced DC FB1-4001A Motor $3100 (including freight & import taxes)
Curtis 1231C Controller $2608 (including freight & import taxes)
Curtis PB6 Pot Box $140 (including freight & import taxes)
Recharging Socket & Plug $15
Turbo Timer $15
Motor Bracket/Mounts $80
Gearbox/Motor Adapter Plate $1112
Calibre Battery Chargers (8) $708
Thomas Vacuum Pump & Switch $110
Digital 200v DC Voltmeter $24 (including freight)
Digital 500A DC Ammeter + Shunt $74 (including freight)
200V DC 10A Solid State Relays(2) $154 (including freight)
160V 250A DC Circuit Breaker $175 (including freight)
SW200 Main Contactor $137 (including freight)
Extraction Fans for Battery Box $18 (including freight)
High Voltage Fuses & Holders (2) $180 (including freight)
70mm2 Welding "Main" Cable (12m) $202
Inertia (Crash) Cutoff Switch $112 (including freight)
Choke Cable (for circuit breaker) $25
Aluminium Cooling Plate $68
MDC2485 Deep Cycle Batteries (12) $2580
Materials for Rear Battery Box $40
New Recharging Plug & Socket $250 (including freight)
TOTAL (so far)....................$11,927 NZ Dollars (approx $9100 USD)
While the whole project seems like quite a lot of money as a lump sum, it was spread out over a year and not so noticeable that way. Unfortunately around $2000 of the whole conversion was simply wasted in freight costs which happens when you're down here on the bottom of the world. The currency difference stung a little too. Don't be put off however. My conversion has only cost so much because I want an EV that will perform well in on the highway and general city traffic too. You could easily build an EV for half the cost if highway capability isn't needed.
Basically I wanted to create a car that dispels the myth that EV's are all slow, lethargic jokes on wheels. :) It's cost more than originally planned but it's absolutely worth it.
I hope this and the FAQ section proves useful, especially to the other Kiwi EV Converters out there!
Watch the conversion unfold right here!A
The battery pack consists of twelve individual 12 volt deep-cycle Hella Endurant MDC24/85 batteries, rated at 85A/hrs and 515 CCA.
The 12 batteries will be connected in series to create 144 volts. Electric Vehicles must use deep-cycle batteries as they can handle a serious discharge much better than regular car or marine batteries. They're more expensive than marine or car batteries but last generally six times longer under standard use. While my battery pack is small with an unimpressive range, New Plymouth is a small town that's less than 10km (6 miles) across so range isn't important in our situation. The typical life expectancy of deep cycle lead acid batteries in an EV is generally about 3 years.
- The charging system I originally used consisted of 12 individual Calibre 3.5 Amp Australian made chargers - one for each battery. The reason for this setup was the cost. Overall this method cost me $708 NZ ($490 USD), as opposed to $1400 NZ for a single "pack" charger.
Now while this method was definitely cheap, it was slooooow. It ended up being cheaper to buy a $1400 Zivan 16 amp pack charger than replacing all the individual 12v chargers with 16 amp ones. So now that I've bought a 16 amp pack charger I'd have to say that I prefer it for speed and convenience.
The budget so far is made up of EV Conversion related purchases only. I have not included paint or basic tools as these are not applicable to every EV, and many tools I will use for other purposes. My own labour has been excluded also, unless I'm paying someone else for it of course!
The EV budget so far in New Zealand dollars is:
Advanced DC FB1-4001A Motor $3100 (including freight & import taxes)
Curtis 1231C Controller $2608 (including freight & import taxes)
Curtis PB6 Pot Box $140 (including freight & import taxes)
Recharging Socket & Plug $15
Turbo Timer $15
Motor Bracket/Mounts $80
Gearbox/Motor Adapter Plate $1112
Calibre Battery Chargers (8) $708
Thomas Vacuum Pump & Switch $110
Digital 200v DC Voltmeter $24 (including freight)
Digital 500A DC Ammeter + Shunt $74 (including freight)
200V DC 10A Solid State Relays(2) $154 (including freight)
160V 250A DC Circuit Breaker $175 (including freight)
SW200 Main Contactor $137 (including freight)
Extraction Fans for Battery Box $18 (including freight)
High Voltage Fuses & Holders (2) $180 (including freight)
70mm2 Welding "Main" Cable (12m) $202
Inertia (Crash) Cutoff Switch $112 (including freight)
Choke Cable (for circuit breaker) $25
Aluminium Cooling Plate $68
MDC2485 Deep Cycle Batteries (12) $2580
Materials for Rear Battery Box $40
New Recharging Plug & Socket $250 (including freight)
TOTAL (so far)....................$11,927 NZ Dollars (approx $9100 USD)
While the whole project seems like quite a lot of money as a lump sum, it was spread out over a year and not so noticeable that way. Unfortunately around $2000 of the whole conversion was simply wasted in freight costs which happens when you're down here on the bottom of the world. The currency difference stung a little too. Don't be put off however. My conversion has only cost so much because I want an EV that will perform well in on the highway and general city traffic too. You could easily build an EV for half the cost if highway capability isn't needed.
Basically I wanted to create a car that dispels the myth that EV's are all slow, lethargic jokes on wheels. :) It's cost more than originally planned but it's absolutely worth it.
I hope this and the FAQ section proves useful, especially to the other Kiwi EV Converters out there!
Watch the conversion unfold right here!A
2009년 9월 20일 일요일
Converting Auto Mission car to the EV
http://www.evconvert.com/faq/can-i-use-an-automatic-transmission
Q :
My wife doesn’t drive a stick, why don’t any of the EVs have an automatic transmission? Do I have to use an AC motor in order to keep the automatic transmission?
A :
You can make an automatic EV with DC just as easily as you can AC. The trick with an automatic is you need to have the motor slowly spinning ALL of the time to keep the hydraulics pumped up. Maybe you could find an old donor car that uses a CVT transmission, I don’t think they need the hydraulic pressure and they are automatic.
There are some AC motor setups that have been designed to replace the transmission as well, which might be what you are referencing. No reason you couldn’t run a DC motor with the same gear box, that is if someone will sell it to you and you can adapt it to the spline.
Depending on your driving you don’t necessarily have to shift that much, if at all. I only did city driving on my EV (under 40mph) and pretty much left it in 2nd gear all of the time.
Lee Hart posted the following on the EVList a while back:
If it’s a budget conversion, I’d say keep the automatic. Let the electric motor idle, just as it would with the ICE. Use a motor with a rear shaft, so you can put a pulley on it and drive the old alternator and other accessories (air conditioner, etc.).
Idling wastes a little power; it will generally draw 1-2 amps from the propulsion pack when stopped. This is low enough that you could leave it idling for a day or two before it discharged the pack.
Automatics that don’t have a locking torque converter are a little less efficient, so they will cost you 10% or so in range.
Comments 17
1.— Jim Calvert Aug 12, 2007 23:44 PM #
I have a 1988 VW Rabbit Cabriolet convertible that I would like to convert into an EV. The only problem is that it has an automatic transmission. Any possibility of finding an AC motor that could replace the transmission on this particular car? ... or how well would my car operate if I keep the auto transmission? Thanks.
2.— Joel Aug 13, 2007 18:22 PM #
I have a 1993 nissan 240sx. And i have the starter hooked up to a switch. This is so that i can turn it off at stops and goign downhill, and start it when needed. Without getting to as to why I do it, I leave the car in drive all the time. when the light turns green I just start it and the engine will crank then as soon as it gets to about 700rpms it engages into drive and drives off.It will engage as low as 500rpms and the only problem is that if the motor has too much time to “speed up” then when it doesn engage you’ll burnout…if thats the case. there’s no problem with leaving it automatic other than a small delay from when the motor spins and your wheel spin. if you would like the transsmission can be locked to 1st or second gear by selecting L1 or 1 depending on the transmission. reverse will work. Park will too, something manual transmissions cant do with an electric motor.
3.— Gavin Shoebridge Aug 24, 2007 17:54 PM #
Hey Joel, that sounds like a good idea.
I wish I’d thought of that years ago. Imagine a switch on the accelerator that starts the gas engine as soon as it’s even slightly pressed.
I know gas engines use something like three times the fuel (compared to driving) when starting, but it would still save quite a bit of money. The engine would start without even thinking about it.
Might be a bad thing too in a manual car.
There’s a few things that would need tweaking (ie: making sure the starter doesn’t try to start the engine while coasting at 60mph) but it could be a nice idea.
4.— Chris Jan 12, 2008 12:29 PM #
Lets look at some old race car technology. They sometimes use a direct hub in place of the torque convertor, which is why you would have to “idle” your motor. I’d like to try an auto trans, left in drive and take off in low with an electric motor. Although you’d want to choose a trans without a vacuum modulator and throttle valve linkage. (if that is possible)
5.— Dave Jun 01, 2008 13:49 PM #
A swith to cut/start the engine is a great idea. But bypassing the neutral saftey swith (so you can leave it in drive) is not. Your car could start in gear and take off on you. Also, it’s REALLY hard on the starter to start the engine like that, worse if it’s a manual and you’re starting it in gear. You’ll burn the starter out on no time. Starters are not cheap.
6.— Eric Jun 02, 2008 15:06 PM #
And if your car is like mine and you have hydraulic brakes, engine off = oh crap.
7.— Dan P. Jun 03, 2008 03:43 AM #
“And if your car is like mine and you have hydraulic brakes, engine off = oh crap”
This is a Vacuum Booster issue; you still have brakes just not the power assistance.
8.— Charles Jun 08, 2008 21:48 PM #
Can anyone recommend a good direct drive ac or dc engine setup that would effectively replace an AT tranny? Cars like the Tesla use one from ACPropulsion. Any others out there?
9.— Patrick D. Aug 24, 2008 15:54 PM #
What exactly is a CVT transmission? Also, would a front-wheel drive car with an automatic transmission have one? I’m thinking about converting a 2003 PT Cruiser to an EV in the future (after I’ve paid off the loan).
Patrick.
10.— EVdude Aug 24, 2008 18:00 PM #
A CVT is a Continuously Variable Transmission. the motor stays turning at a certain RPM but when you push the pedal a pulley moves further from the engine and axle pulleys and tightens up the belt. as the belt tightens the axle pulley speed increases thereby increasing the speed. if you need further info google CVT transmission.
11.— Dan P. Aug 25, 2008 03:35 AM #
Here is a link discussing diagnostics for vibrations with a CVT transmissions; it has some good information on which vehicles have them and pictures.
Pictures are good! I like pictures…
http://www.vibratesoftware.com/html_help/html/Diagnosis/Reference/CVT_Transmissions.htm
12.— EVdude Aug 25, 2008 21:46 PM #
Thanks for the link Dan. I didn’t know that they had invented a two pulley CVT but obviously they have by the looks of the pictures. a good example of a CVT transmisssion is the new John Deere mowers. instead of a 4 or 5 speed shifter they have an accelerator pedal and apparently these are attached to CVT transmission. they are very fun to drive at high speed(i clocked 9 mph on mine)
13.— Dan P. Sep 03, 2008 01:54 AM #
History of the CVT
“Leonardo DaVinci sketched the first CVT in 1490. Dutch automaker DAF first started using CVTs in their cars in the late 1950s; however technology limitations made CVTs unsuitable for engines with more than around 100 horsepower. In the late 80s and early 90s, Subaru offered a CVT in their Justy mini-car, while Honda used one in the high-mileage Honda Civic HX of the late 90s.
Improved CVTs capable of handling more powerful engines were developed in the late 90s and 2000s, and CVTs can now be found in cars from Nissan, Audi, Honda, Ford, GM, and other automakers.”
http://cars.about.com/od/thingsyouneedtoknow/a/CVT.htm
Also See: Variomatic
http://en.wikipedia.org/wiki/Variomatic
14.— Jeff Mar 14, 2009 15:07 PM #
Why wouldn’t an overdrive unit work as a replacement for a transmission to extend range at higher speeds.
15.— Scott Mar 21, 2009 23:40 PM #
Why would you need a torque converter in this case? If you were to get rid of that, what other “hydraulics” would need to be powered?
16.— JohnG Mar 22, 2009 20:24 PM #
There are virtually no automatic transmissions, bar the Power Glide, that have a low enough drag (or high enough efficiency) to justify having them; torque converter or not.
You cannot simply operate an A/T sans a converter because without hydraulic pressure (“engine” running ALL the time – even at idle) you can’t engage ANY gear.
The slight motor efficiency loss at low speeds (<35 MPH) of a single gear set-up more than outweigh any benefits of a transmission, any type of transmission.
17.— DanP. Aug 01, 2009 15:47 PM #
The main reason that I’d want to use an automatic transmission is that if anyone else drove the vehicle they could just put it in park when they were done driving and I wouldn’t be worrying the whole time if they’d remembered to set the parking brake when they got out. Also not all vehicle Parking Brakes are equal…
Q :
My wife doesn’t drive a stick, why don’t any of the EVs have an automatic transmission? Do I have to use an AC motor in order to keep the automatic transmission?
A :
You can make an automatic EV with DC just as easily as you can AC. The trick with an automatic is you need to have the motor slowly spinning ALL of the time to keep the hydraulics pumped up. Maybe you could find an old donor car that uses a CVT transmission, I don’t think they need the hydraulic pressure and they are automatic.
There are some AC motor setups that have been designed to replace the transmission as well, which might be what you are referencing. No reason you couldn’t run a DC motor with the same gear box, that is if someone will sell it to you and you can adapt it to the spline.
Depending on your driving you don’t necessarily have to shift that much, if at all. I only did city driving on my EV (under 40mph) and pretty much left it in 2nd gear all of the time.
Lee Hart posted the following on the EVList a while back:
If it’s a budget conversion, I’d say keep the automatic. Let the electric motor idle, just as it would with the ICE. Use a motor with a rear shaft, so you can put a pulley on it and drive the old alternator and other accessories (air conditioner, etc.).
Idling wastes a little power; it will generally draw 1-2 amps from the propulsion pack when stopped. This is low enough that you could leave it idling for a day or two before it discharged the pack.
Automatics that don’t have a locking torque converter are a little less efficient, so they will cost you 10% or so in range.
Comments 17
1.— Jim Calvert Aug 12, 2007 23:44 PM #
I have a 1988 VW Rabbit Cabriolet convertible that I would like to convert into an EV. The only problem is that it has an automatic transmission. Any possibility of finding an AC motor that could replace the transmission on this particular car? ... or how well would my car operate if I keep the auto transmission? Thanks.
2.— Joel Aug 13, 2007 18:22 PM #
I have a 1993 nissan 240sx. And i have the starter hooked up to a switch. This is so that i can turn it off at stops and goign downhill, and start it when needed. Without getting to as to why I do it, I leave the car in drive all the time. when the light turns green I just start it and the engine will crank then as soon as it gets to about 700rpms it engages into drive and drives off.It will engage as low as 500rpms and the only problem is that if the motor has too much time to “speed up” then when it doesn engage you’ll burnout…if thats the case. there’s no problem with leaving it automatic other than a small delay from when the motor spins and your wheel spin. if you would like the transsmission can be locked to 1st or second gear by selecting L1 or 1 depending on the transmission. reverse will work. Park will too, something manual transmissions cant do with an electric motor.
3.— Gavin Shoebridge Aug 24, 2007 17:54 PM #
Hey Joel, that sounds like a good idea.
I wish I’d thought of that years ago. Imagine a switch on the accelerator that starts the gas engine as soon as it’s even slightly pressed.
I know gas engines use something like three times the fuel (compared to driving) when starting, but it would still save quite a bit of money. The engine would start without even thinking about it.
Might be a bad thing too in a manual car.
There’s a few things that would need tweaking (ie: making sure the starter doesn’t try to start the engine while coasting at 60mph) but it could be a nice idea.
4.— Chris Jan 12, 2008 12:29 PM #
Lets look at some old race car technology. They sometimes use a direct hub in place of the torque convertor, which is why you would have to “idle” your motor. I’d like to try an auto trans, left in drive and take off in low with an electric motor. Although you’d want to choose a trans without a vacuum modulator and throttle valve linkage. (if that is possible)
5.— Dave Jun 01, 2008 13:49 PM #
A swith to cut/start the engine is a great idea. But bypassing the neutral saftey swith (so you can leave it in drive) is not. Your car could start in gear and take off on you. Also, it’s REALLY hard on the starter to start the engine like that, worse if it’s a manual and you’re starting it in gear. You’ll burn the starter out on no time. Starters are not cheap.
6.— Eric Jun 02, 2008 15:06 PM #
And if your car is like mine and you have hydraulic brakes, engine off = oh crap.
7.— Dan P. Jun 03, 2008 03:43 AM #
“And if your car is like mine and you have hydraulic brakes, engine off = oh crap”
This is a Vacuum Booster issue; you still have brakes just not the power assistance.
8.— Charles Jun 08, 2008 21:48 PM #
Can anyone recommend a good direct drive ac or dc engine setup that would effectively replace an AT tranny? Cars like the Tesla use one from ACPropulsion. Any others out there?
9.— Patrick D. Aug 24, 2008 15:54 PM #
What exactly is a CVT transmission? Also, would a front-wheel drive car with an automatic transmission have one? I’m thinking about converting a 2003 PT Cruiser to an EV in the future (after I’ve paid off the loan).
Patrick.
10.— EVdude Aug 24, 2008 18:00 PM #
A CVT is a Continuously Variable Transmission. the motor stays turning at a certain RPM but when you push the pedal a pulley moves further from the engine and axle pulleys and tightens up the belt. as the belt tightens the axle pulley speed increases thereby increasing the speed. if you need further info google CVT transmission.
11.— Dan P. Aug 25, 2008 03:35 AM #
Here is a link discussing diagnostics for vibrations with a CVT transmissions; it has some good information on which vehicles have them and pictures.
Pictures are good! I like pictures…
http://www.vibratesoftware.com/html_help/html/Diagnosis/Reference/CVT_Transmissions.htm
12.— EVdude Aug 25, 2008 21:46 PM #
Thanks for the link Dan. I didn’t know that they had invented a two pulley CVT but obviously they have by the looks of the pictures. a good example of a CVT transmisssion is the new John Deere mowers. instead of a 4 or 5 speed shifter they have an accelerator pedal and apparently these are attached to CVT transmission. they are very fun to drive at high speed(i clocked 9 mph on mine)
13.— Dan P. Sep 03, 2008 01:54 AM #
History of the CVT
“Leonardo DaVinci sketched the first CVT in 1490. Dutch automaker DAF first started using CVTs in their cars in the late 1950s; however technology limitations made CVTs unsuitable for engines with more than around 100 horsepower. In the late 80s and early 90s, Subaru offered a CVT in their Justy mini-car, while Honda used one in the high-mileage Honda Civic HX of the late 90s.
Improved CVTs capable of handling more powerful engines were developed in the late 90s and 2000s, and CVTs can now be found in cars from Nissan, Audi, Honda, Ford, GM, and other automakers.”
http://cars.about.com/od/thingsyouneedtoknow/a/CVT.htm
Also See: Variomatic
http://en.wikipedia.org/wiki/Variomatic
14.— Jeff Mar 14, 2009 15:07 PM #
Why wouldn’t an overdrive unit work as a replacement for a transmission to extend range at higher speeds.
15.— Scott Mar 21, 2009 23:40 PM #
Why would you need a torque converter in this case? If you were to get rid of that, what other “hydraulics” would need to be powered?
16.— JohnG Mar 22, 2009 20:24 PM #
There are virtually no automatic transmissions, bar the Power Glide, that have a low enough drag (or high enough efficiency) to justify having them; torque converter or not.
You cannot simply operate an A/T sans a converter because without hydraulic pressure (“engine” running ALL the time – even at idle) you can’t engage ANY gear.
The slight motor efficiency loss at low speeds (<35 MPH) of a single gear set-up more than outweigh any benefits of a transmission, any type of transmission.
17.— DanP. Aug 01, 2009 15:47 PM #
The main reason that I’d want to use an automatic transmission is that if anyone else drove the vehicle they could just put it in park when they were done driving and I wouldn’t be worrying the whole time if they’d remembered to set the parking brake when they got out. Also not all vehicle Parking Brakes are equal…
2009년 9월 19일 토요일
How to Make Graphene
A simple way to deposit thin films of carbon could lead to cheaper solar cells.
By Prachi Patel
Monday, April 14, 2008
E-mail Audio »
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Graphene--a flat single layer of carbon atoms--can transport electrons at remarkable speeds, making it a promising material for electronic devices. Until recently, researchers had been able to make only small flakes of the material, and only in small quantities. However, Rutgers University researchers have developed an easy way to make transparent graphene films that are a few centimeters wide and one to five nanometers thick.
Flexible process: A new fabrication method developed by researchers at Rutgers University can deposit a film of graphene--an atom-thick sheet of carbon--on almost any substrate, including the flexible plastic shown here. The films could be used in thin-film transistors or as conductive electrodes for organic solar cells.
Credit: Manish Chhowalla, Rutgers University
Thin films of graphene could provide a cheap replacement for the transparent, conductive indium tin oxide electrodes used in organic solar cells. They could also replace the silicon thin-film transistors common in display screens. Graphene can transport electrons tens of times faster than silicon, so graphene-based transistors could work faster and consume less power. (See "Graphene Transistors" and "Better Graphene Transistors.")
In fact, Rutgers materials science and engineering professor Manish Chhowalla and his colleagues used their graphene films to make prototype transistors and organic solar calls. In a recent Nature Nanotechnology paper, they showed that they can deposit the transparent films on any substrate, including glass and flexible plastic. Chhowalla says that the method could be adapted to a larger scale to coat "meters and meters of substrates with graphene films," using roll-to-roll processing, a technique being developed to make large flexible electronic circuits.
By contrast, current techniques for making graphene yield small quantities of the material, fit only for experimental use. One common technique is called the "Scotch tape method," in which a piece of tape is used to peel graphene flakes off of a chunk of graphite, which is essentially a stack of graphene sheets. This results in micrometer-sized graphene fragments, which are placed between electrodes to make a transistor. "But if you talk about large-scale devices, you want to make macroscopic [sheets]," says Hannes Schniepp, a graphene researcher at Princeton University. For that, you need to guide the assembly of smaller graphene pieces over a large area, Schniepp says, which is exactly what the Rutgers researchers do.
Story continues below
The researchers start by making a suspension of graphene oxide flakes. They oxidize graphite flakes with sulphuric or nitric acid. This inserts oxygen atoms between individual graphene sheets and forces them apart, resulting in graphene oxide sheets, which are suspended in water.
The suspension is filtered through a membrane that has 25-nanometer-wide pores. Water passes through the pores, but the graphene oxide flakes, each of which is a few micrometers wide and about one nanometer thick, cover the pores. This happens in a regulated fashion, Chhowalla says. When a flake covers a pore, water is directed to its uncovered neighbors, which in turn get covered, until flakes are distributed across the entire surface. "The method allows you to deposit single layers of graphene," Chhowalla says. "[It] results in a nearly uniform film deposited on the membrane." The researchers place the film-coated side of the membrane on a substrate, such as glass or plastic, and wash away the membrane with acetone. Finally, they expose the film to a chemical called hydrazine, which converts the graphene oxide into graphene.
Continued from page 1
By Prachi Patel
Monday, April 14, 2008
E-mail Audio »
Listen - FlashListen - MP3Subscribe to podcastWhat is this?Powered by Print Favorite Share »
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James Tour, a chemistry professor at Rice University, says that this is "certainly the easiest method I've seen for making [graphene thin films] over large areas." He thinks that the process could easily be converted into a larger, commercial-scale manufacturing technique. "It's very amenable for rapid production," he says. "It's not going to take much to get these things produced ... and cover large areas."
Chhowalla and his colleagues control the thickness of the film by changing the suspension's volume. A volume of 20 milliliters results in a film that is mostly one to two nanometers in thickness, while an 80-milliliter suspension results in films that are mainly three to five nanometers thick. The thinner films are 95 percent transparent. The researchers have used the films as the transparent electrodes in organic solar cells. They have also made transistors by placing their films on a silicon substrate and depositing gold electrodes on them.
The graphene films need a lot more work. Right now, the transistors do not carry as much current as those made from individual graphene flakes, which, the researchers speculate, is because of overlapping flakes in their films. For high-quality transistors, they will need to make single-layer graphene films with no overlap. They also need to improve the conductivity of their film: indium tin oxide is still hundreds of times more conductive. Organic solar cells with indium tin oxide electrodes are between 3 percent and 5 percent efficient. "With graphene thin-film electrodes, we get 0.1 percent," Chhowalla says, "but these are proof-of-concept devices and of course will improve with time."
Tour believes that the film holds more promise for organic solar cells than for transistors. Many researchers are also studying carbon nanotube films as a way to replace indium tin oxide coatings on solar cells. But Tour says that graphene would be "possibly easier than using carbon nanotubes because of the greater availability of the material." The industry might also find it easier to adopt graphene because of the concerns that some people have about the effects of carbon nanotubes on the environment.
By Prachi Patel
Monday, April 14, 2008
E-mail Audio »
Listen - FlashListen - MP3Subscribe to podcastWhat is this?Powered by Print Favorite Share »
Digg this Add to del.icio.us Add to Reddit Add to Facebook Slashdot It! Stumble It! Add to Mixx Add to Newsvine Add to Connotea Add to CiteUlike Add to Furl Googlize this Add to Rojo Add to MyWeb
Graphene--a flat single layer of carbon atoms--can transport electrons at remarkable speeds, making it a promising material for electronic devices. Until recently, researchers had been able to make only small flakes of the material, and only in small quantities. However, Rutgers University researchers have developed an easy way to make transparent graphene films that are a few centimeters wide and one to five nanometers thick.
Flexible process: A new fabrication method developed by researchers at Rutgers University can deposit a film of graphene--an atom-thick sheet of carbon--on almost any substrate, including the flexible plastic shown here. The films could be used in thin-film transistors or as conductive electrodes for organic solar cells.
Credit: Manish Chhowalla, Rutgers University
Thin films of graphene could provide a cheap replacement for the transparent, conductive indium tin oxide electrodes used in organic solar cells. They could also replace the silicon thin-film transistors common in display screens. Graphene can transport electrons tens of times faster than silicon, so graphene-based transistors could work faster and consume less power. (See "Graphene Transistors" and "Better Graphene Transistors.")
In fact, Rutgers materials science and engineering professor Manish Chhowalla and his colleagues used their graphene films to make prototype transistors and organic solar calls. In a recent Nature Nanotechnology paper, they showed that they can deposit the transparent films on any substrate, including glass and flexible plastic. Chhowalla says that the method could be adapted to a larger scale to coat "meters and meters of substrates with graphene films," using roll-to-roll processing, a technique being developed to make large flexible electronic circuits.
By contrast, current techniques for making graphene yield small quantities of the material, fit only for experimental use. One common technique is called the "Scotch tape method," in which a piece of tape is used to peel graphene flakes off of a chunk of graphite, which is essentially a stack of graphene sheets. This results in micrometer-sized graphene fragments, which are placed between electrodes to make a transistor. "But if you talk about large-scale devices, you want to make macroscopic [sheets]," says Hannes Schniepp, a graphene researcher at Princeton University. For that, you need to guide the assembly of smaller graphene pieces over a large area, Schniepp says, which is exactly what the Rutgers researchers do.
Story continues below
The researchers start by making a suspension of graphene oxide flakes. They oxidize graphite flakes with sulphuric or nitric acid. This inserts oxygen atoms between individual graphene sheets and forces them apart, resulting in graphene oxide sheets, which are suspended in water.
The suspension is filtered through a membrane that has 25-nanometer-wide pores. Water passes through the pores, but the graphene oxide flakes, each of which is a few micrometers wide and about one nanometer thick, cover the pores. This happens in a regulated fashion, Chhowalla says. When a flake covers a pore, water is directed to its uncovered neighbors, which in turn get covered, until flakes are distributed across the entire surface. "The method allows you to deposit single layers of graphene," Chhowalla says. "[It] results in a nearly uniform film deposited on the membrane." The researchers place the film-coated side of the membrane on a substrate, such as glass or plastic, and wash away the membrane with acetone. Finally, they expose the film to a chemical called hydrazine, which converts the graphene oxide into graphene.
Continued from page 1
By Prachi Patel
Monday, April 14, 2008
E-mail Audio »
Listen - FlashListen - MP3Subscribe to podcastWhat is this?Powered by Print Favorite Share »
Digg this Add to del.icio.us Add to Reddit Add to Facebook Slashdot It! Stumble It! Add to Mixx Add to Newsvine Add to Connotea Add to CiteUlike Add to Furl Googlize this Add to Rojo Add to MyWeb
James Tour, a chemistry professor at Rice University, says that this is "certainly the easiest method I've seen for making [graphene thin films] over large areas." He thinks that the process could easily be converted into a larger, commercial-scale manufacturing technique. "It's very amenable for rapid production," he says. "It's not going to take much to get these things produced ... and cover large areas."
Chhowalla and his colleagues control the thickness of the film by changing the suspension's volume. A volume of 20 milliliters results in a film that is mostly one to two nanometers in thickness, while an 80-milliliter suspension results in films that are mainly three to five nanometers thick. The thinner films are 95 percent transparent. The researchers have used the films as the transparent electrodes in organic solar cells. They have also made transistors by placing their films on a silicon substrate and depositing gold electrodes on them.
The graphene films need a lot more work. Right now, the transistors do not carry as much current as those made from individual graphene flakes, which, the researchers speculate, is because of overlapping flakes in their films. For high-quality transistors, they will need to make single-layer graphene films with no overlap. They also need to improve the conductivity of their film: indium tin oxide is still hundreds of times more conductive. Organic solar cells with indium tin oxide electrodes are between 3 percent and 5 percent efficient. "With graphene thin-film electrodes, we get 0.1 percent," Chhowalla says, "but these are proof-of-concept devices and of course will improve with time."
Tour believes that the film holds more promise for organic solar cells than for transistors. Many researchers are also studying carbon nanotube films as a way to replace indium tin oxide coatings on solar cells. But Tour says that graphene would be "possibly easier than using carbon nanotubes because of the greater availability of the material." The industry might also find it easier to adopt graphene because of the concerns that some people have about the effects of carbon nanotubes on the environment.
Graphene Sheets Get Easier To Manufacture
from the can't-be-too-thin dept.
grunaura writes
"South Korean researchers have devised a way to create graphene sheets one centimeter square using a hydrocarbon vapor on heated nickel. It's touted as being more efficient than the current process where graphene sheets are pressed, and there is evidence that 'the quality of graphene grown by chemical vapour deposition is as high as mechanically cleaved graphene.' Graphene is relatively new, but not to Slashdot. This round of news highlighting the technology focuses on the bendable nature of graphene sheets, as opposed to the memory applications or capacitive properties discussed here previously. These films are the closest we have come to superconductors at room temperature."
grunaura writes
"South Korean researchers have devised a way to create graphene sheets one centimeter square using a hydrocarbon vapor on heated nickel. It's touted as being more efficient than the current process where graphene sheets are pressed, and there is evidence that 'the quality of graphene grown by chemical vapour deposition is as high as mechanically cleaved graphene.' Graphene is relatively new, but not to Slashdot. This round of news highlighting the technology focuses on the bendable nature of graphene sheets, as opposed to the memory applications or capacitive properties discussed here previously. These films are the closest we have come to superconductors at room temperature."
Making Graphene 101, Ozyilmaz' Group
수작업으로 그래핀을 만드는 동영상
http://www.youtube.com/watch?v=rphiCdR68TE
How Bilayer Graphene Got a Bandgap
수작업으로 nono graphe만드는 법
Synthesis of Carbon nanotube
한국의 과학자는 그래핀판을 쉽게 만들수 있도록 하고 있다.
Graphene Sheets Get Easier To Manufacture
Posted by kdawson on Sun Jan 18, 2009 12:42 AM
from the can't-be-too-thin dept.
grunaura writes
"South Korean researchers have devised a way to create graphene sheets one centimeter square using a hydrocarbon vapor on heated nickel. It's touted as being more efficient than the current process where graphene sheets are pressed, and there is evidence that 'the quality of graphene grown by chemical vapour deposition is as high as mechanically cleaved graphene.' Graphene is relatively new, but not to Slashdot. This round of news highlighting the technology focuses on the bendable nature of graphene sheets, as opposed to the memory applications or capacitive properties discussed here previously. These films are the closest we have come to superconductors at room temperature."
http://www.youtube.com/watch?v=rphiCdR68TE
How Bilayer Graphene Got a Bandgap
수작업으로 nono graphe만드는 법
Synthesis of Carbon nanotube
한국의 과학자는 그래핀판을 쉽게 만들수 있도록 하고 있다.
Graphene Sheets Get Easier To Manufacture
Posted by kdawson on Sun Jan 18, 2009 12:42 AM
from the can't-be-too-thin dept.
grunaura writes
"South Korean researchers have devised a way to create graphene sheets one centimeter square using a hydrocarbon vapor on heated nickel. It's touted as being more efficient than the current process where graphene sheets are pressed, and there is evidence that 'the quality of graphene grown by chemical vapour deposition is as high as mechanically cleaved graphene.' Graphene is relatively new, but not to Slashdot. This round of news highlighting the technology focuses on the bendable nature of graphene sheets, as opposed to the memory applications or capacitive properties discussed here previously. These films are the closest we have come to superconductors at room temperature."
Maxwell Ultracapacitors to Capture Subway Braking Power
Maxwell Ultracapacitors to Capture Subway Braking Power
The South Korean government is testing Maxwell Technologies' ultracapacitors for subway regenerative braking systems. .Maxwell Technologies' ultracapacitors are hitting the brakes on South Korean subways - a test of the technology's promise to outperform batteries in capturing and discharging electricity.
The San Diego-based company announced late Wednesday that its ultracapacitors would be used in a regenerative braking project being done by the Korean Railroad Research Institute in a Korean subway system.
That's a new market for Maxwell (NASDAQ: MXWL), one of the more established companies in the field of ultracapacitors. Maxwell and its competitors – including APowerCap Technologies, EnerG2 Inc. and EEstor – say their products can beat batteries on power storage and lifespan measures (see Is This the Way to Build Electric Cars?).
One application for ultracapacitors that's been getting a lot of attention lately is regenerative braking, which captures the kinetic energy from brakes. Regenerative braking is used on some hybrid cars, such as the Toyota Prius and Honda Insight, to help charge their batteries. Subway systems, including the world's largest in New York, have also experimented with the technology.
To supply the Korean subway test, Maxwell shipped 72 of its 48-volt ultracapacitor modules to contractor Woojin Industrial Systems earlier this year, where they were used to test a 740-volt regenerative braking system on the Gyengsan light rail transit track. In October, Maxwell shipped another 220 modules to be part of a 1500-volt DC system to be installed by the second quarter of 2009.
That system is scheduled to be demonstrated in mid-2009. But Maxwell said preliminary tests showed that the regenerative braking systems using its modules could reduce grid power consumption by more than 20 percent, or enough to pay back the system's cost in four years.
Capacitors store energy as an electrical field, rather than chemically as batteries do. That means they can charge and discharge faster, and over more life cycles, than batteries, at the expense of "energy density," or amount of power stored per unit of weight. Ultracapacitors promise to solve that problem through improved energy density, using a variety of methods.
Maxwell has sold its ultracapacitors to other customers, for uses including regenerative braking systems for bus companies in China and Europe, and to provide backup power for wind turbine blade pitch control systems built by Germany's LTi REEnergy.
The Economist magazine has pointed to ultracapacitors as a potential replacement for batteries as the energy storage technology of choice - if the technology can prove to work as well as its backers say it can. Investors seem willing to place bets on that question.
EnerG2 Inc. raised $8.5 million for its first round to develop an ultracapacitor for storing energy in electric cars and electronic devices. The Seattle company, founded in 2003, raised the money from OVP Venture Partners, Firelake Capital Management, WRF Capital, and Northwest Energy Angels.
APowerCap, a Ukraine-based company that said it has received funding in 2006 from Ukrainian venture capital firm TechInvest, recently received a funding commitment for between $5 and $20 million from an investment firm called EastOne Group, according to Dow Jones' Clean Technology Investor (via VentureBeat).
AS for EEStor, the Cedar Park, Texas-based company has announced deals with Toronto-based Zenn Motors and Eugene, Ore.-based Light Electric Vehicle Co. to provide ultracapacitors that it said could replace batteries in electric cars.
But EEStor has seen continual delays in launching its product, which it first promised to deliver by the end of 2007. Recently, EEStor CEO said in a blog post that the company would not deliver its ultracapacitors to market by the end of 2008 because of a lack of funding (see Sounds Like EEStor Has Delayed Again).
The South Korean government is testing Maxwell Technologies' ultracapacitors for subway regenerative braking systems. .Maxwell Technologies' ultracapacitors are hitting the brakes on South Korean subways - a test of the technology's promise to outperform batteries in capturing and discharging electricity.
The San Diego-based company announced late Wednesday that its ultracapacitors would be used in a regenerative braking project being done by the Korean Railroad Research Institute in a Korean subway system.
That's a new market for Maxwell (NASDAQ: MXWL), one of the more established companies in the field of ultracapacitors. Maxwell and its competitors – including APowerCap Technologies, EnerG2 Inc. and EEstor – say their products can beat batteries on power storage and lifespan measures (see Is This the Way to Build Electric Cars?).
One application for ultracapacitors that's been getting a lot of attention lately is regenerative braking, which captures the kinetic energy from brakes. Regenerative braking is used on some hybrid cars, such as the Toyota Prius and Honda Insight, to help charge their batteries. Subway systems, including the world's largest in New York, have also experimented with the technology.
To supply the Korean subway test, Maxwell shipped 72 of its 48-volt ultracapacitor modules to contractor Woojin Industrial Systems earlier this year, where they were used to test a 740-volt regenerative braking system on the Gyengsan light rail transit track. In October, Maxwell shipped another 220 modules to be part of a 1500-volt DC system to be installed by the second quarter of 2009.
That system is scheduled to be demonstrated in mid-2009. But Maxwell said preliminary tests showed that the regenerative braking systems using its modules could reduce grid power consumption by more than 20 percent, or enough to pay back the system's cost in four years.
Capacitors store energy as an electrical field, rather than chemically as batteries do. That means they can charge and discharge faster, and over more life cycles, than batteries, at the expense of "energy density," or amount of power stored per unit of weight. Ultracapacitors promise to solve that problem through improved energy density, using a variety of methods.
Maxwell has sold its ultracapacitors to other customers, for uses including regenerative braking systems for bus companies in China and Europe, and to provide backup power for wind turbine blade pitch control systems built by Germany's LTi REEnergy.
The Economist magazine has pointed to ultracapacitors as a potential replacement for batteries as the energy storage technology of choice - if the technology can prove to work as well as its backers say it can. Investors seem willing to place bets on that question.
EnerG2 Inc. raised $8.5 million for its first round to develop an ultracapacitor for storing energy in electric cars and electronic devices. The Seattle company, founded in 2003, raised the money from OVP Venture Partners, Firelake Capital Management, WRF Capital, and Northwest Energy Angels.
APowerCap, a Ukraine-based company that said it has received funding in 2006 from Ukrainian venture capital firm TechInvest, recently received a funding commitment for between $5 and $20 million from an investment firm called EastOne Group, according to Dow Jones' Clean Technology Investor (via VentureBeat).
AS for EEStor, the Cedar Park, Texas-based company has announced deals with Toronto-based Zenn Motors and Eugene, Ore.-based Light Electric Vehicle Co. to provide ultracapacitors that it said could replace batteries in electric cars.
But EEStor has seen continual delays in launching its product, which it first promised to deliver by the end of 2007. Recently, EEStor CEO said in a blog post that the company would not deliver its ultracapacitors to market by the end of 2008 because of a lack of funding (see Sounds Like EEStor Has Delayed Again).
Breakthrough In Use of Graphene For Ultracapacitors
Breakthrough In Use of Graphene For Ultracapacitors
Posted by kdawson on Wed Sep 17, 2008 02:59 AM
from the high-credit-limit dept.
Hugh Pickens writes
"Researchers at the University of Texas at Austin have achieved a breakthrough in the use of a one-atom thick graphene for storing electrical charge in ultracapacitors. They believe their development shows promise that graphene could eventually double the capacity of existing ultracapacitors. 'Through such a device, electrical charge can be rapidly stored on the graphene sheets, and released from them as well for the delivery of electrical current and, thus, electrical power,' says one of the researchers. Two main methods exist to store electrical energy: in rechargeable batteries and in ultracapacitors, which are becoming increasingly commercialized but are not yet well known to the public. Some advantages of ultracapacitors over traditional energy storage devices such as batteries include: higher power capability, longer life, a wider thermal operating range, lighter, more flexible packaging and lower maintenance. Graphene has a surface area of 2,630 square meters, almost the area of a football field, per gram of material."
Posted by kdawson on Wed Sep 17, 2008 02:59 AM
from the high-credit-limit dept.
Hugh Pickens writes
"Researchers at the University of Texas at Austin have achieved a breakthrough in the use of a one-atom thick graphene for storing electrical charge in ultracapacitors. They believe their development shows promise that graphene could eventually double the capacity of existing ultracapacitors. 'Through such a device, electrical charge can be rapidly stored on the graphene sheets, and released from them as well for the delivery of electrical current and, thus, electrical power,' says one of the researchers. Two main methods exist to store electrical energy: in rechargeable batteries and in ultracapacitors, which are becoming increasingly commercialized but are not yet well known to the public. Some advantages of ultracapacitors over traditional energy storage devices such as batteries include: higher power capability, longer life, a wider thermal operating range, lighter, more flexible packaging and lower maintenance. Graphene has a surface area of 2,630 square meters, almost the area of a football field, per gram of material."
MIT Builds Efficient Nanowire Storage to Replace Car Batteries
CAMBRIDGE, Mass. — Sometimes the cliché fits: It looks like a bomb went off—not necessarily in this lab, but somewhere, with the aftermath seemingly carted here. The gutted remains of a sedan, its engine exposed, the seats ripped out of the frame, sits encased in cables. At other workstations the focus is a single part—an isolated camshaft, an alternator hooked up to test apparatus. It would be easy to misinterpret this place and think that researchers at MIT’s Lab for Electromagnetic and Electronic Systems (LEES) are either piecing back together some shattered car or entering the Automotive X Prize. In fact, each of these experiments has different methodologies, but many have the same goal: automotive efficiency, by any means necessary.
The wired car, for example, is an effort to test more detailed diagnostic systems, with sensors that detect changes in the system’s electrical signature—and maybe even warn you before the starter motor fails. And the modifications made to the alternator would let it run at 30 percent greater efficiency, with a smoother electrical system translating to about 1 mpg in improved mileage. Researchers estimate that the increased cost for the manufacturer would be about $5.
One of the most promising experiments here is tucked away in what appears to be the messiest part of the entire lab, a small room littered with hand tools and testing gear. Joel Schindall, the associate director of LEES, pulls a tray out of a cabinet and flips it open. Inside are four black squares, like overturned tiles from a Magnetic Poetry set. If my job was to clean out this lab, I would probably take one look at these unassuming little things and fling the entire tray into the nearest trash can. Because unless they’re under an electron microscope, vertically aligned carbon nanotube arrays don’t look like much.
The point of these particular arrays is to capture ions and eventually give traditional rechargeable batteries a run for their money. The focus of Schindall’s research is ultracapacitors, which store drastically less energy than a battery but have essentially none of the drawbacks. In any capacitor, there’s no battery memory caused by partial discharging and no reduction in capacity with each recharge. “They never wear out, they have no electrolyte, they don’t have any chemistry taking place in them,” Schindall says. “It’s just an electric field that stores the energy. So you can recharge a capacitor a gazillion times. It’s very efficient—just the internal resistance of the wires.” The ions cling electrostatically to materials in a capacitor, which also allows for much quicker charge times. And by avoiding the chemical reaction that drives traditional batteries, there’s no real danger of a capacitor suddenly overloading—or exploding like a laptop’s lithium-ion battery pack. (For more on how this technology works, read senior automotive editor Mike Allen’s new take on why ultracapacitors could replace batteries in hybrid cars.)
The problem with capacitors—and the reason they’ve taken such a back seat to batteries since they were first stumbled upon in the ’60s—is capacity. Even ultracapacitors can manage only a fraction of the power of a lead-acid or lithium-ion battery. So the recipe for a better ultracapacitor is more surface area. Researchers have already expanded capacity with the addition of activated carbon coatings, which are porous enough to provide an effective surface area that’s 10,000 times greater than the materials previously used to gather ions. Around four years ago, Schindall was reading about various experiments that utilized nanowire arrays, when he experienced—though no scientist, Schindall included, would ever actually put it this way—the proverbial “eureka” moment.
By replacing the porous activated carbon used in ultracapacitors with tightly bunched nanotubes, Schindall believed that the ion-collecting surface area could be increased by as much as five. Since current ultracapacitors can store around 5 percent of the energy in an equivalent-size battery, the addition of nanowires could bring this up to 25 percent. “And you can also operate [the ultracapacitor] at a higher voltage with the nanotubes, and that’s about another factor of two in energy,” he says. “We are hopeful—we haven’t proven it—that we can get up somewhere between 25 and 50 percent of a battery’s energy. At that point, it becomes a compelling device for many applications.”
Those applications could include not only electric vehicles, where the benefits of unlimited charge cycles and less overload-prone storage are clear, but in hybrid cars as well. The math gets a little complicated here, but Schindall says that even standard ultracapacitors, with their relatively paltry 5 percent storage, are potential competitors for the pack in his Toyota Prius. “In order to prolong the life of the battery in my car, they only use it over the middle 10 to 15 percent of its range,” he says. “So actually I’m only using perhaps 15 percent of the capacity. With an ultracapacitor you can use it all, or almost all. So the difference between 5 percent and 15 percent is not nearly as severe.”
According to Schindall, ultracapacitors would also outlive the car, possibly solving the complicated warranty issues surrounding hybrids and, whenever they’re finally released commercially, plug-in hybrids. If nanotube ultracapacitors can reach that 25 or 50 percent mark, then they could not only compete with the batteries currently used by Toyota, but thanks to their ability to discharge without risk, they could provide even longer ranges. “I try to contain myself, because it hasn’t been proven yet, but it could be a real paradigm change,” Schindall says.
The process of creating the nanowire arrays is relatively straightforward—a tiny piece of conductive substrate is coated with a catalyst, and then placed in a vacuum chamber. The chamber is then filled with carbon gas, and the square is heated until a black, sootlike coating appears. After about 10 minutes, the tile is complete, and the nanowires are fully grown. The challenge has been in reaching the theoretical capacity that Schindall’s team originally calculated. So far, the nanotubes can match the energy storage of standard ultracapacitors, but the goal remains to boost that capacity by a factor of five or even 10. “A couple of years ago, we thought we were six months to a year away. And that time has come and gone,” he says.
The next step for this project is to create test cells about the size of watch batteries to be distributed to existing ultracapacitor manufacturers. The team will also release its latest results, but by allowing companies to independently verify that data, Schindall believes it could demonstrate the commercial viability of the nanotube approach. He hopes to have those test cells ready within a year, or possibly as soon as a few months. Still, it could take years for ultracapacitors of any kind to reach the kind of production volume and capacity necessary to rival batteries in the marketplace. So for now, these nano-dusted squares are going back in their tray and back on the shelf to fight for energy storage supremacy another day.
The wired car, for example, is an effort to test more detailed diagnostic systems, with sensors that detect changes in the system’s electrical signature—and maybe even warn you before the starter motor fails. And the modifications made to the alternator would let it run at 30 percent greater efficiency, with a smoother electrical system translating to about 1 mpg in improved mileage. Researchers estimate that the increased cost for the manufacturer would be about $5.
One of the most promising experiments here is tucked away in what appears to be the messiest part of the entire lab, a small room littered with hand tools and testing gear. Joel Schindall, the associate director of LEES, pulls a tray out of a cabinet and flips it open. Inside are four black squares, like overturned tiles from a Magnetic Poetry set. If my job was to clean out this lab, I would probably take one look at these unassuming little things and fling the entire tray into the nearest trash can. Because unless they’re under an electron microscope, vertically aligned carbon nanotube arrays don’t look like much.
The point of these particular arrays is to capture ions and eventually give traditional rechargeable batteries a run for their money. The focus of Schindall’s research is ultracapacitors, which store drastically less energy than a battery but have essentially none of the drawbacks. In any capacitor, there’s no battery memory caused by partial discharging and no reduction in capacity with each recharge. “They never wear out, they have no electrolyte, they don’t have any chemistry taking place in them,” Schindall says. “It’s just an electric field that stores the energy. So you can recharge a capacitor a gazillion times. It’s very efficient—just the internal resistance of the wires.” The ions cling electrostatically to materials in a capacitor, which also allows for much quicker charge times. And by avoiding the chemical reaction that drives traditional batteries, there’s no real danger of a capacitor suddenly overloading—or exploding like a laptop’s lithium-ion battery pack. (For more on how this technology works, read senior automotive editor Mike Allen’s new take on why ultracapacitors could replace batteries in hybrid cars.)
The problem with capacitors—and the reason they’ve taken such a back seat to batteries since they were first stumbled upon in the ’60s—is capacity. Even ultracapacitors can manage only a fraction of the power of a lead-acid or lithium-ion battery. So the recipe for a better ultracapacitor is more surface area. Researchers have already expanded capacity with the addition of activated carbon coatings, which are porous enough to provide an effective surface area that’s 10,000 times greater than the materials previously used to gather ions. Around four years ago, Schindall was reading about various experiments that utilized nanowire arrays, when he experienced—though no scientist, Schindall included, would ever actually put it this way—the proverbial “eureka” moment.
By replacing the porous activated carbon used in ultracapacitors with tightly bunched nanotubes, Schindall believed that the ion-collecting surface area could be increased by as much as five. Since current ultracapacitors can store around 5 percent of the energy in an equivalent-size battery, the addition of nanowires could bring this up to 25 percent. “And you can also operate [the ultracapacitor] at a higher voltage with the nanotubes, and that’s about another factor of two in energy,” he says. “We are hopeful—we haven’t proven it—that we can get up somewhere between 25 and 50 percent of a battery’s energy. At that point, it becomes a compelling device for many applications.”
Those applications could include not only electric vehicles, where the benefits of unlimited charge cycles and less overload-prone storage are clear, but in hybrid cars as well. The math gets a little complicated here, but Schindall says that even standard ultracapacitors, with their relatively paltry 5 percent storage, are potential competitors for the pack in his Toyota Prius. “In order to prolong the life of the battery in my car, they only use it over the middle 10 to 15 percent of its range,” he says. “So actually I’m only using perhaps 15 percent of the capacity. With an ultracapacitor you can use it all, or almost all. So the difference between 5 percent and 15 percent is not nearly as severe.”
According to Schindall, ultracapacitors would also outlive the car, possibly solving the complicated warranty issues surrounding hybrids and, whenever they’re finally released commercially, plug-in hybrids. If nanotube ultracapacitors can reach that 25 or 50 percent mark, then they could not only compete with the batteries currently used by Toyota, but thanks to their ability to discharge without risk, they could provide even longer ranges. “I try to contain myself, because it hasn’t been proven yet, but it could be a real paradigm change,” Schindall says.
The process of creating the nanowire arrays is relatively straightforward—a tiny piece of conductive substrate is coated with a catalyst, and then placed in a vacuum chamber. The chamber is then filled with carbon gas, and the square is heated until a black, sootlike coating appears. After about 10 minutes, the tile is complete, and the nanowires are fully grown. The challenge has been in reaching the theoretical capacity that Schindall’s team originally calculated. So far, the nanotubes can match the energy storage of standard ultracapacitors, but the goal remains to boost that capacity by a factor of five or even 10. “A couple of years ago, we thought we were six months to a year away. And that time has come and gone,” he says.
The next step for this project is to create test cells about the size of watch batteries to be distributed to existing ultracapacitor manufacturers. The team will also release its latest results, but by allowing companies to independently verify that data, Schindall believes it could demonstrate the commercial viability of the nanotube approach. He hopes to have those test cells ready within a year, or possibly as soon as a few months. Still, it could take years for ultracapacitors of any kind to reach the kind of production volume and capacity necessary to rival batteries in the marketplace. So for now, these nano-dusted squares are going back in their tray and back on the shelf to fight for energy storage supremacy another day.
ULTRA CAPACITOR TUNING
Some time ago I received mail from an employee of NuinTEK, Korea. The reason was my mini article concerning the Condensor Plane. As described, this plane is powered by an so called GoldCap which has 3.3 F at 2.5 V.
NuinTEK manufactures such ultracapacitors, also known as EDLC (Electric Double Layer Capacitor) or Ultra Capacitors. The technical data of their Ultra Capacitors are superior to the originally supplied GoldCap.
Lets look at the dimensions of the original GoldCap. 23 by 13 mm (length x diameter). The closest resemblence in NuinTEKs portfolio is a Ultra Capacitor with 3 F at 2.7 V, beeing substantially smaller having 21 x 8 mm.
A NuinTEK Ultra Capacitor with similar mechanical dimensions has as much as 20 F at 2.5 V or even 25 F at 2.3 V.
There are other Ultra Capacitors with different sizes and values available at NuinTEK.
According to speech of NuinTEK, they are one of the biggest manufacturers of motor running capacitors and metallized film capacitors in Korea and also newly developed Ultra Capacitors for mass production as an extension of business.
--------------------------------------------------------------------------------
Having heard so many good news about NuinTEKs Ultra Capacitors, it´s time to prove their superiority under "real life" conditions.
NuinTEK provided me with samples of their Ultra Capacitor production, so I could do some investigations. I used the Condensor Plane as test bed since it was the reason for NuinTEK to get in touch with me.
In the picture you see (from left to rigth)
GoldCap 3,3 F @ 2,5 V (Original)
Ultra Capacitor 3 F @ 2,7 V
Ultra Capacitor 10 F @ 2,3 V
Ultra Capacitor 20 F @ 2,5 V
Ultra Capacitor 25 F @ 2,3 V
just to give an impression of the different sizes.
Since at the moment we have harsh weather which is likely to smash the little Condensor Plane, I have to take my measures on the workbench and perhaps deliver values under real flight conditions next summer.
I fixed the model in a vice and took the motor running times with a stopwatch. As comparison I first evaluated the original GoldCap, afterwards the Ultra Capacitor samples from NuinTEK.
Icharge max [A]
tI<30 mA [s]
tmotor on[s]
mass [g] 2)
length x diameter [mm]
Original GoldCap
3,3 F @ 2,5 V
1,24
16
48
4
23 x 12,6
NuinTEK Ultra Capacitor
3 F @ 2,7 V
1,25
14
38
2
21 x 8,2
NuinTEK Ultra Capacitor
10 F @ 2,3 V
1,19
65
151
4
30,6 x 10
NuinTEK Ultra Capacitor
20 F @ 2,5 V
1,13
120 1)
382
6,5
27 x 16,2
NuinTEK Ultra Capacitor
25 F @ 2,3 V
1,07
130 1)
362
8
26,4 x 16
1) the 20 F and 25 F types were charged only until the charge current reaches 50 mA since they did not reach the expected 30 mA cutoff current even after several minutes.
2) approximate value (balance with 2 grams resolution, weighed several samples for each type).
The capacitors were charged with a laboratory power supply at 2.5 V until charge current ceases and reached 30 mA cutoff current. Right afterwards the motor was started and the time until stop of the airscrew was taken. In stationary operation at 2.5 V the motor consumes 0.6 A so that can be taken as the starting current for the discharge cycle.
The reason for all charging currents staying beneath 1.3 A is the current limiting circuitry of the power supply. Without limitation the maximum currents may reach 30 to 150 A respectively (depending on the type of Ultra Capacitor) according to the data sheet of the capacitors. With the given setup the supply voltage broke down to 0.6 V at the beginning and slowly rose with progression of the charge process.
The times resulted from the described measuring procedure are not to be taken as values for the time the plane will be airborne. To get an idea on that we can take the 30 seconds the Condensor Plane made with the original GoldCap. Since the 10 F Ultra Capacitor has similar weight one can expect around 1.5 minutes of flight time taking into account the values from the table above.
Whether the bigger types of Ultra Capacitors will result in even longer flight times may be in doubt since they are at least 60% heavier than the original GoldCap. This is of some significance since the mass of the plane alone without energy storage facilities is only 12 grams.
One remarkable fact is that the 25 F capacitor yields shorter motor on times than the smaller 20 F type.
Here has to be stated that the charge times become shorter for every charge-discharge cycle, while the motor on times remain unchanged. E.g. the 20 F type in three sucessive cycles first needed 180, then 120 and 112 seconds, respectively, to reach the cutoff current of 50 mA. In all three cycles the motor ran exactly 382 seconds.
There seems to take place a forming process affecting the storable energy per time.
The shorter motor run times find their explanation in less energy stored in the capacitor, caused by the smaller resistance of the 25 F type in conjunction with the fold back characteristic of my lab power supply.
--------------------------------------------------------------------------------
There are several conceivable possibilities for using Ultra Capacitors. The usage as energy source for a model airplane is probably rather the exception. On the other hand NuinTEK has really big devices with 60 F which are superior to batteries in energy density by a factor of 5 to 10 according to NuinTEKs technical infos. Using some of these, connected in series and in parallel to get sufficient voltage and capacity, may make it even possible to launch a small radio controlled airplane.
Other ideas are:
LED flashlight (perhaps in conjunction with a step up converter from Zetex)
back up energy for battery operated devices while changing batteries
toys
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NuinTEK manufactures such ultracapacitors, also known as EDLC (Electric Double Layer Capacitor) or Ultra Capacitors. The technical data of their Ultra Capacitors are superior to the originally supplied GoldCap.
Lets look at the dimensions of the original GoldCap. 23 by 13 mm (length x diameter). The closest resemblence in NuinTEKs portfolio is a Ultra Capacitor with 3 F at 2.7 V, beeing substantially smaller having 21 x 8 mm.
A NuinTEK Ultra Capacitor with similar mechanical dimensions has as much as 20 F at 2.5 V or even 25 F at 2.3 V.
There are other Ultra Capacitors with different sizes and values available at NuinTEK.
According to speech of NuinTEK, they are one of the biggest manufacturers of motor running capacitors and metallized film capacitors in Korea and also newly developed Ultra Capacitors for mass production as an extension of business.
--------------------------------------------------------------------------------
Having heard so many good news about NuinTEKs Ultra Capacitors, it´s time to prove their superiority under "real life" conditions.
NuinTEK provided me with samples of their Ultra Capacitor production, so I could do some investigations. I used the Condensor Plane as test bed since it was the reason for NuinTEK to get in touch with me.
In the picture you see (from left to rigth)
GoldCap 3,3 F @ 2,5 V (Original)
Ultra Capacitor 3 F @ 2,7 V
Ultra Capacitor 10 F @ 2,3 V
Ultra Capacitor 20 F @ 2,5 V
Ultra Capacitor 25 F @ 2,3 V
just to give an impression of the different sizes.
Since at the moment we have harsh weather which is likely to smash the little Condensor Plane, I have to take my measures on the workbench and perhaps deliver values under real flight conditions next summer.
I fixed the model in a vice and took the motor running times with a stopwatch. As comparison I first evaluated the original GoldCap, afterwards the Ultra Capacitor samples from NuinTEK.
Icharge max [A]
tI<30 mA [s]
tmotor on[s]
mass [g] 2)
length x diameter [mm]
Original GoldCap
3,3 F @ 2,5 V
1,24
16
48
4
23 x 12,6
NuinTEK Ultra Capacitor
3 F @ 2,7 V
1,25
14
38
2
21 x 8,2
NuinTEK Ultra Capacitor
10 F @ 2,3 V
1,19
65
151
4
30,6 x 10
NuinTEK Ultra Capacitor
20 F @ 2,5 V
1,13
120 1)
382
6,5
27 x 16,2
NuinTEK Ultra Capacitor
25 F @ 2,3 V
1,07
130 1)
362
8
26,4 x 16
1) the 20 F and 25 F types were charged only until the charge current reaches 50 mA since they did not reach the expected 30 mA cutoff current even after several minutes.
2) approximate value (balance with 2 grams resolution, weighed several samples for each type).
The capacitors were charged with a laboratory power supply at 2.5 V until charge current ceases and reached 30 mA cutoff current. Right afterwards the motor was started and the time until stop of the airscrew was taken. In stationary operation at 2.5 V the motor consumes 0.6 A so that can be taken as the starting current for the discharge cycle.
The reason for all charging currents staying beneath 1.3 A is the current limiting circuitry of the power supply. Without limitation the maximum currents may reach 30 to 150 A respectively (depending on the type of Ultra Capacitor) according to the data sheet of the capacitors. With the given setup the supply voltage broke down to 0.6 V at the beginning and slowly rose with progression of the charge process.
The times resulted from the described measuring procedure are not to be taken as values for the time the plane will be airborne. To get an idea on that we can take the 30 seconds the Condensor Plane made with the original GoldCap. Since the 10 F Ultra Capacitor has similar weight one can expect around 1.5 minutes of flight time taking into account the values from the table above.
Whether the bigger types of Ultra Capacitors will result in even longer flight times may be in doubt since they are at least 60% heavier than the original GoldCap. This is of some significance since the mass of the plane alone without energy storage facilities is only 12 grams.
One remarkable fact is that the 25 F capacitor yields shorter motor on times than the smaller 20 F type.
Here has to be stated that the charge times become shorter for every charge-discharge cycle, while the motor on times remain unchanged. E.g. the 20 F type in three sucessive cycles first needed 180, then 120 and 112 seconds, respectively, to reach the cutoff current of 50 mA. In all three cycles the motor ran exactly 382 seconds.
There seems to take place a forming process affecting the storable energy per time.
The shorter motor run times find their explanation in less energy stored in the capacitor, caused by the smaller resistance of the 25 F type in conjunction with the fold back characteristic of my lab power supply.
--------------------------------------------------------------------------------
There are several conceivable possibilities for using Ultra Capacitors. The usage as energy source for a model airplane is probably rather the exception. On the other hand NuinTEK has really big devices with 60 F which are superior to batteries in energy density by a factor of 5 to 10 according to NuinTEKs technical infos. Using some of these, connected in series and in parallel to get sufficient voltage and capacity, may make it even possible to launch a small radio controlled airplane.
Other ideas are:
LED flashlight (perhaps in conjunction with a step up converter from Zetex)
back up energy for battery operated devices while changing batteries
toys
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Battery/Ultracapacitor System for Small Electric Vehicles
Battery/Ultracapacitor System for Small Electric Vehicles
27 April 2009
Configuration of an EV with battery pack and ultracapacitor. From Li et al.(2009) Click to enlarge.
Researchers at the Illinois Institute of Technology and Allborg University (Denmark) are studying a hybrid battery/ultracapacitor system for small electric vehicles. They presented a paper on their work at the recent SAE 2009 World Congress in Detroit.
In the system, the batteries function as the main energy storage source of the vehicle, supplying average power to the load. The ultracapacitors are used to meet the peak power demands during transients. In their study, the researchers connected the battery pack and ultracapacitor bank in parallel to the DC link with bi-directional two quadrant buck-boost converters. To control the system, they propose a power flow management methodology based on load demand.
The vehicle target was a small electric vehicle (similar to a neighborhood elecric vehicle, NEV) with a speed limit of 40-50 km/h (25-31 mph), maximum power of 40 kW, and a weight of about 800 kg. The battery pack comprised two parallel strings of 14 series-connected 12 V NiMH batteries (Saft NHE 10-100). The ultracapacitor was a Maxwell BMOD0063 module with a nominal voltage of 125V.
The battery pack had a minimum allowable state of charge of 20%. The minimum allowable state of charge of the ultracapacitor was 25%.
In this topology, the stress and oscillations of the battery current is reduced which results in the size and cost reduction of the battery and increases the lifetime. Presented results show that the power management based on hybrid system reduces the stress in battery current without sacrificing the performance.
The desired performance is achieved by the power flow control of two sources in acceleration and regenerative braking modes while providing a reduced size of battery with longer life time and less subjection to stress and oscillations.Li et al. (2009)
Resources
•Zhihao Li, Omer Onar, Alireza Khaligh, Erik Schaltz (2009) Design, Control, and Power Management of a Battery/Ultra-Capacitor Hybrid System for Small Electric vehicles (SAE 2009-01-1387)
April 27, 2009 in Electric (Battery) | Permalink | Comments (4) | TrackBack (0)
Comments
How about a couple of low power DC motors to drive the front wheels direct from the supercapacitors, with batteries/inverter and a larger AC motor to drive the rear axle?
To get the energy from the wheels -> motor -> inverter -> DC converter -> batteries then back again might lose you 1/4 to 1/3 of your braking energy.
If your only going from wheels -> motor -> caps and back again, you should get much better round trip efficiency.
Supercaps will be very useful to buffer the batteries during fast charging
27 April 2009
Configuration of an EV with battery pack and ultracapacitor. From Li et al.(2009) Click to enlarge.
Researchers at the Illinois Institute of Technology and Allborg University (Denmark) are studying a hybrid battery/ultracapacitor system for small electric vehicles. They presented a paper on their work at the recent SAE 2009 World Congress in Detroit.
In the system, the batteries function as the main energy storage source of the vehicle, supplying average power to the load. The ultracapacitors are used to meet the peak power demands during transients. In their study, the researchers connected the battery pack and ultracapacitor bank in parallel to the DC link with bi-directional two quadrant buck-boost converters. To control the system, they propose a power flow management methodology based on load demand.
The vehicle target was a small electric vehicle (similar to a neighborhood elecric vehicle, NEV) with a speed limit of 40-50 km/h (25-31 mph), maximum power of 40 kW, and a weight of about 800 kg. The battery pack comprised two parallel strings of 14 series-connected 12 V NiMH batteries (Saft NHE 10-100). The ultracapacitor was a Maxwell BMOD0063 module with a nominal voltage of 125V.
The battery pack had a minimum allowable state of charge of 20%. The minimum allowable state of charge of the ultracapacitor was 25%.
In this topology, the stress and oscillations of the battery current is reduced which results in the size and cost reduction of the battery and increases the lifetime. Presented results show that the power management based on hybrid system reduces the stress in battery current without sacrificing the performance.
The desired performance is achieved by the power flow control of two sources in acceleration and regenerative braking modes while providing a reduced size of battery with longer life time and less subjection to stress and oscillations.Li et al. (2009)
Resources
•Zhihao Li, Omer Onar, Alireza Khaligh, Erik Schaltz (2009) Design, Control, and Power Management of a Battery/Ultra-Capacitor Hybrid System for Small Electric vehicles (SAE 2009-01-1387)
April 27, 2009 in Electric (Battery) | Permalink | Comments (4) | TrackBack (0)
Comments
How about a couple of low power DC motors to drive the front wheels direct from the supercapacitors, with batteries/inverter and a larger AC motor to drive the rear axle?
To get the energy from the wheels -> motor -> inverter -> DC converter -> batteries then back again might lose you 1/4 to 1/3 of your braking energy.
If your only going from wheels -> motor -> caps and back again, you should get much better round trip efficiency.
Supercaps will be very useful to buffer the batteries during fast charging
EEStor Ultra Capacitors: The Science Explained
EEStor Ultra Capacitors: The Science Explained
We finally find out about the science behind the secretive EEStor Capacitors from the Austin American Statesman:
Think of it as a grilled-cheese sandwich: The bread holds opposite charges. The cheese helps maintain the opposing charges, even as it separates the bread and keeps those charges from canceling each other out. Then you stack one layer atop another.
"It's real simple," Hebner said. "It's just two pieces of metal with some material in between them. You put a voltage across them and they store a certain amount of charge."
The hard part is making them efficient enough to store more and more power. Most research has focused on ways to increase the surface area of the plates so they can hold a greater charge. To use the grilled-cheese example, the nooks and crannies of a rough piece of bread can hold more butter than a smoother slice of the same size.
Earlier this year, the Massachusetts Institute of Technology said its researchers were developing plates made of super-small nanotubes that would vastly increase surface area on the same size plate.
Weir and Nelson [of EEStor] have gone the other direction: They're focusing on the cheese instead of the bread. Different types of cheese — and thinner slices of it — help store more powerful charges. EEStor's patent describes a method that takes a really good cheese and creates an extremely thin layer of it.
Read the whole story at the ::American Statesman via ::Clean Break and then go for lunch.
Ultra Capacitors Boost Electric Car Efficiency
Ultra Capacitors Boost Electric Car Efficiency
What's one of the best way to kill batteries? If you answered "charge or discharge to fast" than you're right! In today's plug in electric vehicles (PHEV's for short) one of the main causes for battery life to shorten is the fact that acceleration draws a large amount of power from the batteries.
On the flip side the re-generative braking can't capture all the power that's produced because batteries have a limit to how much power can be dumped into them (know as C). Many batteries will have a rating of 1C up to 5C (5C batteries are usually lithium variants).
Before we move any further we need to understand the C value. Batteries have an amp hour (Ah) rating. Let's say that your batteries hold 200Ah. To figure out how much peak current your battery can 'give up' we multiply the amp hour rating by the C rating. So if the C rating was 2C you multiply 200 X 2 and come up with 400 amps. That battery could provide 400 amps continuously.
There are actually two C ratings on batteries: one for charging and one for discharging. The charging C rating is usually lower than the discharge rating.
So what's the problem? Well, we want a car that can charge very fast, and one that can dump a lot of amps when discharging as well. The trade off is that by doing this you shorten the life of the battery pack.
That's where the idea of using capacitors (really big ones) comes in. If you don't know what a capacitor is it's basically little battery. The difference is it can be charged and discharged very rapidly many many times. The trade off with capacitors? Well, they don't hold nearly as much energy as any standard chemical battery.
By combining the two together we can get the best of both worlds. While charging the battery you can fully charge the capacitor (you should be able to charge it that fast, but it depends on how much power you have available) in a couple seconds and slowly charge the batteries. By charging the batteries slower they will last quite a bit longer.
The beauty of the ultra capacitors is when you're accelerating and braking. Accelerating an electric motor draws a huge amount of power which the capacitor can provide without putting such a huge load on the batteries. After you've reached speed the capacitor could draw an even amount of power to recharge itself. Since we're not putting so much strain on the batteries they won't wear out as fast.
Now we come to the best part... re-generative braking. Since a capacitor can capture a lot of energy in a short period of time much more energy can be captured when you brake.
In the end it all adds up to electric cars and hybrids that are more efficient, but don't cost more. I can't wait to see some of the test results from some cars with these ultra capacitors in them.
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Maxwell Technologies BMOD0110-16.2V Ultracapacitors
Click image to enlarge
--------------------------------------------------------------------------------
Downloads
Datasheet
User Manual
--------------------------------------------------------------------------------
16 Volt Power Module Overview
The Power-type ultracapacitor product line gives customers in the automotive and transportation sector a much wider range of choices to meet their energy storage and power delivery requirements.
The modules are specifically engineered for hybrid vehicle drive trains, automotive subsystems and other heavy duty applications that require the lowest equivalent series resistance (ESR) and highest efficiency available.
In addition to meeting or exceeding demanding automotive and transportation application requirements for both watt-hours of energy storage and watts of power delivery per kilogram, all of these products will perform reliably for more than one million discharge-recharge cycles.
The proprietary architecture and material science on which BOOSTCAP® products are based enable continued leadership in controlling costs, flexibility in product offerings and allow application specific performance tailoring. The cells used in the modules operate at 2.7 volts, enabling them to store more energy and deliver more power per unit volume than any other commercially available ultracapacitor products.
16 Volt Power Module Features:
16.2V Operating Voltage
Ultra Low internal resistance
Over 1M duty cycles
Individually balanced cells
Ultracapacitors: the future of electric cars or the 'cold fusion' of autovation?
ZENN Motors says its electric car will cruise for 250 miles on a single five-minute charge. Skeptics cry shenanigans.
By Mark Clayton | Staff writer of The Christian Science Monitor
from the April 16, 2008 edition
Print this Buzz up!Email and shareRepublish E-mail newsletters RSS
Page 1 of 3
Reporter Mark Clayton discusses the prospect of a new type of electric vehicle from Toronto-based firm ZENN Motors.
Ian Clifford wants to start a global revolution by building a practical, everyday car with no gasoline engine, no batteries, and no emissions.
While big Detroit automakers ponder a future plug-in car that goes 40 miles on a battery charge before its gas engine kicks in, Mr. Clifford's tiny ZENN Motor, a Toronto maker of low-speed electric cars, announced in March that it will build a new highway-speed (80 m.p.h.) model that goes 250 miles on a charge – and can recharge in just five minutes.
Having no batteries, the new "cityZENN" model will use a breakthrough version of a common electrical storage device called an ultracapacitor to store power from a wall socket, the company says. Fuel costs to operate it would be about one-tenth of today's gas-powered vehicle.
If that astounding claim is real (and there are many skeptics), it could revolutionize automotive travel by making all-electric cars competitive with gas-powered vehicles and easing the world's dependence on oil.
"The big problem has always been the battery and its limits," says Clifford, ZENN's founder and CEO in a phone interview. "This new technology is a 180-degree shift that represents the end of fossil fuel as a transportation fuel."
That's because the same ultracapacitor technology could be used across the grid to provide cheap electric storage for wind and solar power, he says. In turn, this process could power millions of ultracapacitor vehicles with no emissions at all. With the cars' fast-charge capability, recharging stations could pop up to help make even longer trips routine.
Ultracapacitors – also called supercapacitors – are more powerful cousins of the basic capacitor. With activated carbon at their core to act as a sponge for electrons, ultracapacitors can absorb power – or send a charge – far faster than batteries. They are also far more durable.
First used in the 1960s, ultracapacitors today are widely found in electronic devices such as computers. In cameras, they retract and expand zoom lens. Yet the power stored by today's ultracapacitors is still only about 5 percent as much as a modern lithium-ion battery, far too little to power a car by themselves.
The reported breakthrough was made by ZENN's business partner EEStor, a Cedar Park, Texas, firm headed by respected computer industry veteran Richard Weir, who's named on the company's patent. The company is now nearing commercial production of its new "electrical energy storage unit" or EESU, Clifford says.
But privately held EEStor has had little to say publicly or to the press – and that secretiveness has inspired incredulity among many debating the topic on Internet forums.
But in a break with that tradition, Tom Weir, the company's vice president and general manager, responded to e-mailed questions.
"EEStor's technology has the opportunity to touch every aspect of daily life from very big to very small devices," Mr. Weir writes. "We also see a whole new generation of products ... based around our technology."
Added credibility arrived with the January announcement by Lockheed Martin, the big defense company, of an agreement to use EEStor technology for military and homeland security applications. It refers to the EEStor "ceramic battery" providing "10 times the energy density of lead-acid batteries at 1/10th the weight and volume."
In 2005, Kleiner Perkins Caufield & Byers sunk $3 million into EEStor. ZENN also invested $3 million and will get exclusive rights to retrofit vehicles with the system – and produce new mid-size cars using EESUs.
Mountable option included
Voltage and temperature sensor output included
Compact, rugged, fully enclosed and splash proof design
Applications:
What's one of the best way to kill batteries? If you answered "charge or discharge to fast" than you're right! In today's plug in electric vehicles (PHEV's for short) one of the main causes for battery life to shorten is the fact that acceleration draws a large amount of power from the batteries.
On the flip side the re-generative braking can't capture all the power that's produced because batteries have a limit to how much power can be dumped into them (know as C). Many batteries will have a rating of 1C up to 5C (5C batteries are usually lithium variants).
Before we move any further we need to understand the C value. Batteries have an amp hour (Ah) rating. Let's say that your batteries hold 200Ah. To figure out how much peak current your battery can 'give up' we multiply the amp hour rating by the C rating. So if the C rating was 2C you multiply 200 X 2 and come up with 400 amps. That battery could provide 400 amps continuously.
There are actually two C ratings on batteries: one for charging and one for discharging. The charging C rating is usually lower than the discharge rating.
So what's the problem? Well, we want a car that can charge very fast, and one that can dump a lot of amps when discharging as well. The trade off is that by doing this you shorten the life of the battery pack.
That's where the idea of using capacitors (really big ones) comes in. If you don't know what a capacitor is it's basically little battery. The difference is it can be charged and discharged very rapidly many many times. The trade off with capacitors? Well, they don't hold nearly as much energy as any standard chemical battery.
By combining the two together we can get the best of both worlds. While charging the battery you can fully charge the capacitor (you should be able to charge it that fast, but it depends on how much power you have available) in a couple seconds and slowly charge the batteries. By charging the batteries slower they will last quite a bit longer.
The beauty of the ultra capacitors is when you're accelerating and braking. Accelerating an electric motor draws a huge amount of power which the capacitor can provide without putting such a huge load on the batteries. After you've reached speed the capacitor could draw an even amount of power to recharge itself. Since we're not putting so much strain on the batteries they won't wear out as fast.
Now we come to the best part... re-generative braking. Since a capacitor can capture a lot of energy in a short period of time much more energy can be captured when you brake.
In the end it all adds up to electric cars and hybrids that are more efficient, but don't cost more. I can't wait to see some of the test results from some cars with these ultra capacitors in them.
If you liked this article consider signing up for our newsletter. Simply enter your information below.
Maxwell Technologies BMOD0110-16.2V Ultracapacitors
Click image to enlarge
--------------------------------------------------------------------------------
Downloads
Datasheet
User Manual
--------------------------------------------------------------------------------
16 Volt Power Module Overview
The Power-type ultracapacitor product line gives customers in the automotive and transportation sector a much wider range of choices to meet their energy storage and power delivery requirements.
The modules are specifically engineered for hybrid vehicle drive trains, automotive subsystems and other heavy duty applications that require the lowest equivalent series resistance (ESR) and highest efficiency available.
In addition to meeting or exceeding demanding automotive and transportation application requirements for both watt-hours of energy storage and watts of power delivery per kilogram, all of these products will perform reliably for more than one million discharge-recharge cycles.
The proprietary architecture and material science on which BOOSTCAP® products are based enable continued leadership in controlling costs, flexibility in product offerings and allow application specific performance tailoring. The cells used in the modules operate at 2.7 volts, enabling them to store more energy and deliver more power per unit volume than any other commercially available ultracapacitor products.
16 Volt Power Module Features:
16.2V Operating Voltage
Ultra Low internal resistance
Over 1M duty cycles
Individually balanced cells
Ultracapacitors: the future of electric cars or the 'cold fusion' of autovation?
ZENN Motors says its electric car will cruise for 250 miles on a single five-minute charge. Skeptics cry shenanigans.
By Mark Clayton | Staff writer of The Christian Science Monitor
from the April 16, 2008 edition
Print this Buzz up!Email and shareRepublish E-mail newsletters RSS
Page 1 of 3
Reporter Mark Clayton discusses the prospect of a new type of electric vehicle from Toronto-based firm ZENN Motors.
Ian Clifford wants to start a global revolution by building a practical, everyday car with no gasoline engine, no batteries, and no emissions.
While big Detroit automakers ponder a future plug-in car that goes 40 miles on a battery charge before its gas engine kicks in, Mr. Clifford's tiny ZENN Motor, a Toronto maker of low-speed electric cars, announced in March that it will build a new highway-speed (80 m.p.h.) model that goes 250 miles on a charge – and can recharge in just five minutes.
Having no batteries, the new "cityZENN" model will use a breakthrough version of a common electrical storage device called an ultracapacitor to store power from a wall socket, the company says. Fuel costs to operate it would be about one-tenth of today's gas-powered vehicle.
If that astounding claim is real (and there are many skeptics), it could revolutionize automotive travel by making all-electric cars competitive with gas-powered vehicles and easing the world's dependence on oil.
"The big problem has always been the battery and its limits," says Clifford, ZENN's founder and CEO in a phone interview. "This new technology is a 180-degree shift that represents the end of fossil fuel as a transportation fuel."
That's because the same ultracapacitor technology could be used across the grid to provide cheap electric storage for wind and solar power, he says. In turn, this process could power millions of ultracapacitor vehicles with no emissions at all. With the cars' fast-charge capability, recharging stations could pop up to help make even longer trips routine.
Ultracapacitors – also called supercapacitors – are more powerful cousins of the basic capacitor. With activated carbon at their core to act as a sponge for electrons, ultracapacitors can absorb power – or send a charge – far faster than batteries. They are also far more durable.
First used in the 1960s, ultracapacitors today are widely found in electronic devices such as computers. In cameras, they retract and expand zoom lens. Yet the power stored by today's ultracapacitors is still only about 5 percent as much as a modern lithium-ion battery, far too little to power a car by themselves.
The reported breakthrough was made by ZENN's business partner EEStor, a Cedar Park, Texas, firm headed by respected computer industry veteran Richard Weir, who's named on the company's patent. The company is now nearing commercial production of its new "electrical energy storage unit" or EESU, Clifford says.
But privately held EEStor has had little to say publicly or to the press – and that secretiveness has inspired incredulity among many debating the topic on Internet forums.
But in a break with that tradition, Tom Weir, the company's vice president and general manager, responded to e-mailed questions.
"EEStor's technology has the opportunity to touch every aspect of daily life from very big to very small devices," Mr. Weir writes. "We also see a whole new generation of products ... based around our technology."
Added credibility arrived with the January announcement by Lockheed Martin, the big defense company, of an agreement to use EEStor technology for military and homeland security applications. It refers to the EEStor "ceramic battery" providing "10 times the energy density of lead-acid batteries at 1/10th the weight and volume."
In 2005, Kleiner Perkins Caufield & Byers sunk $3 million into EEStor. ZENN also invested $3 million and will get exclusive rights to retrofit vehicles with the system – and produce new mid-size cars using EESUs.
Mountable option included
Voltage and temperature sensor output included
Compact, rugged, fully enclosed and splash proof design
Applications:
2009년 9월 13일 일요일
"LS, 전기차 부분 수혜 예상" 메리츠證
LS그룹이 전기차 부분에서도 수혜가 예상된다는 평가가 나왔다.
메리츠증권 전용기 연구원은 10일 "LS그룹은 전선과 발전설비 분야 외에도 전기차 부품사업에도 진출해 가시적인 성과를 올리고 있다"며 "전기차 모멘텀은 LS에 플러스 알파가 될 것"이라고 밝혔다.
전 연구원에 따르면 LS산전은 전기차 주요 부품인 배터리 차단 유닛(Battery Disconnect Unit)을 생산하고 있으며, LS 자회사인 엠트론은 2차 전지용 음극제 생산을 더욱 늘릴 계획이다. 또 엠트론이 2008년 인수한 대성전기를 통해 자동차 전장 부품사업에 진출했는데 미래형 자동차의 핵심부품 개발에 착수할 예정이다.
그는 "LS는 미국 세계 최대 권선업체인 SPSX(Superior Essex)를 2008년 인수했다"며 "SPSX는 매출의 70% 정도가 권선에서 발생하고 있고 전기차에는 전기모터가 장착되고 모터에는 권선이 필수적으로 들어간다"고 설명했다.
이어 그는 "기존 1800cc급 자동차 한 대가 전기차로 대체될 경우 4㎏ 정도의 권선 수요가 신규로 발생하고 배기량이 커질수록 증가하는 권선 무게가 커진다"며 "이로 인해 전기차 수요가 본격화하면 권선 수요가 증가해 LS의 SPSX 인수는 매우 성공적인 M&A(인수합병)로 평가받게 될 것"이라고 평가했다.
메리츠증권 전용기 연구원은 10일 "LS그룹은 전선과 발전설비 분야 외에도 전기차 부품사업에도 진출해 가시적인 성과를 올리고 있다"며 "전기차 모멘텀은 LS에 플러스 알파가 될 것"이라고 밝혔다.
전 연구원에 따르면 LS산전은 전기차 주요 부품인 배터리 차단 유닛(Battery Disconnect Unit)을 생산하고 있으며, LS 자회사인 엠트론은 2차 전지용 음극제 생산을 더욱 늘릴 계획이다. 또 엠트론이 2008년 인수한 대성전기를 통해 자동차 전장 부품사업에 진출했는데 미래형 자동차의 핵심부품 개발에 착수할 예정이다.
그는 "LS는 미국 세계 최대 권선업체인 SPSX(Superior Essex)를 2008년 인수했다"며 "SPSX는 매출의 70% 정도가 권선에서 발생하고 있고 전기차에는 전기모터가 장착되고 모터에는 권선이 필수적으로 들어간다"고 설명했다.
이어 그는 "기존 1800cc급 자동차 한 대가 전기차로 대체될 경우 4㎏ 정도의 권선 수요가 신규로 발생하고 배기량이 커질수록 증가하는 권선 무게가 커진다"며 "이로 인해 전기차 수요가 본격화하면 권선 수요가 증가해 LS의 SPSX 인수는 매우 성공적인 M&A(인수합병)로 평가받게 될 것"이라고 평가했다.
전격출력 60kw 전기모터차를 구동하려고합니다.
전격출력 60kw 전기모터차를 구동하려고합니다. 하루에 100km 정도 탄다면 전력량이 얼마정도 될까요? 그전력량 만큼 태양열셀을 구매한다면 몇개의 태양열셀이 필요할까요?
전격 60kw라고 했는데요 한 80마력 정도 인데 그럼 전기가 엄청 소모가 클것인데요.
그리고 무게도 만만치않구요 제어 쪽도 쉽지않는데요.
어찌됐던 전기차를 만들려면 자동차의 속도와 모터 rpm이 얼마이고
몇 v로 운영 되는 모터인지 알아야 이야기 할수 있답니다.
우선 12v 는 5000A가 걸리네요.
24V는 2500A이고 48v는 1250 A가 걸리는데요.
시간당 48v일때 1250A이면
태양전지가요.
25v곱하기 2매 =50v 직렬 연결하면 되구요 .모터가 48v니까 태양전지는 됩니다.
태양전지 용량이 190w 짜리 태양전지판이니까
60kw*0.19kw= 315매 (가로 140cm 세로1m 두께5cm)태양전지판이 315 매이네요.
가만 태양전지 가격만해도 190w짜리가 한장에 약 백만원이니까. 3억천오백만원정도 나오네요.그럼 태양전지판이 25v니까 또2로 곱해야 하구요. 6억삼천만원어치가 올려야 겠네요.
그러나 태양전지는 밧테리에 충전해두었다가 쓰기때문에 태양전지판이 계산대로 많이 필요하지 않답니다.
궁금 한것은 모터 제원이 정확한지요.보통 전기차에는 30kw가 쓰이는데요.이것도 큰데요.
전격 60kw라고 했는데요 한 80마력 정도 인데 그럼 전기가 엄청 소모가 클것인데요.
그리고 무게도 만만치않구요 제어 쪽도 쉽지않는데요.
어찌됐던 전기차를 만들려면 자동차의 속도와 모터 rpm이 얼마이고
몇 v로 운영 되는 모터인지 알아야 이야기 할수 있답니다.
우선 12v 는 5000A가 걸리네요.
24V는 2500A이고 48v는 1250 A가 걸리는데요.
시간당 48v일때 1250A이면
태양전지가요.
25v곱하기 2매 =50v 직렬 연결하면 되구요 .모터가 48v니까 태양전지는 됩니다.
태양전지 용량이 190w 짜리 태양전지판이니까
60kw*0.19kw= 315매 (가로 140cm 세로1m 두께5cm)태양전지판이 315 매이네요.
가만 태양전지 가격만해도 190w짜리가 한장에 약 백만원이니까. 3억천오백만원정도 나오네요.그럼 태양전지판이 25v니까 또2로 곱해야 하구요. 6억삼천만원어치가 올려야 겠네요.
그러나 태양전지는 밧테리에 충전해두었다가 쓰기때문에 태양전지판이 계산대로 많이 필요하지 않답니다.
궁금 한것은 모터 제원이 정확한지요.보통 전기차에는 30kw가 쓰이는데요.이것도 큰데요.
레오카 및 미쓰비시의 전기차 기본사양
1. Reo Motors
1)
전기모터 : 60kw (82hp), 26.5kg 최대토크, 80개의 battery cell,
최대속도 : 100km, max 160km
전기차는 주행성능을 지닌 손색없는 자동차라고 하는데요.
23일 있었던 시승식의 전기자동차는 기아의 1000cc경차 모델인
모닝의 전동식 파워트레인을 결합한 전기차량이라고 해요.
이번에 시승식을 갖은 모닝 전기차는 가솔린 가솔린 엔진을 떼어낸 자리에
무게 75kg의 최대출력 65kW급 수랭식 AC모터와 컨트롤러 박스를 달았으며
최대토크는 26.0kg.m로 미쓰비시 전기경차보다 높아서 순간 가속력이 더 낫다는데요.
배터리는 코캄이 제조한 30kWh급 리튬폴리머 파워팩을 뒷좌석에 장착했으며
차량의 외형과 인테리어, 편의장치는 시판 중인 모닝과 똑같다고 해요.
운전석 옆에 붙은 배터리 충전량 표시장치가 전기차의 정체성을 드러내는 유일한 표식인데요.첨단 자동차로서 뭔가 특별함을 원하는 운전자에겐 실망이겠지만
본래 전기 개조차는 평범함과 실용성이 특성인데요.
시동스위치를 올렸으며 낮은 기계음과 함께 파워브레이크에 철컥하고 압력이 들어차는 소리가 들린다네요.전기차의 정숙함은 일반 차량이라면 묻혀서 넘어갈 기계적 작동음까지 부각시키는 단점도 되는데요.시승차는 5단 수동식 변속기를 달았는데 전기모터의 토크 특성을 고려해서 2단 출발을 시도했다고 해요.
클러치 페달에서 슬쩍 발을 떼자 기계음과 함께 차량이 튀어나가며 제로백은 8초 후반으로 경차 수준을 훌쩍 넘어섰다는데요. 이것도 주행거리를 늘리기 위해 모터출력을 30% 가량 낮춰 놓았다고 해요.
가까운 중부고속도로에 진입하면서 가속페달을 끝까지 밟아봤을때 속도계는 120㎞/h를
쉽게 넘어섰다고 하는데요. 익숙한 엔진소리가 아니라 마치 제트기와 비슷한 소리가 난다고 해요.모닝 전기차는 경차샷시의 특성상 시속 130㎞/h를 넘지 않도록 세팅해놓았지만 시내주행은 물론 고속도로를 타기에 충분한 성능인데요.
핸들이 무겁고 차체반응이 둔한 점은 아쉬웠다네요.
연구소로 돌아와서 확인해보니 모닝 전기차는 배터리팩 무게 때문에 일반 모닝보다
중량이 210kg 더 늘었으며 성인 3명의 무게가 늘면서 경차 특유의 민첩한 조향성이 사라진 것인데요.
대신 강력한 전기 파워트레인 덕분에 고속주행능력은 훨씬 좋아졌고 운전특성을 고려할 때
복잡한 시내 주행보다는 수도권에서 서울로 통근하는 용도로 추천된다고 해요.
회사측은 모닝 전기차가 한번 충전으로 고속도로에서 180∼200㎞ 주행이 가능하며
모든 전기차는 파워를 높이면 배터리 소모가 심해지고 주행거리가 떨어진다는데요.
현재 전기모터, 배터리 기술수준을 고려할 때 모닝 전기차는 힘과
주행거리의 밸런스가 가장 적절하고 상용화에 근접해있다네요.
레오모터스는 모닝 전기차를 아직 시판할 계획이 없다고 하는데요.
거대 완성차업체가 장악한 글로벌 자동차 시장에 직접 뛰어드는 대신 전기파워트레인을 공급하는
핵심 부품업체로서 성장하겠다는 전략이라 일반 소비자들이 이같은 컨셉의 전기경차를 갖고 싶다면
내년에 현대차가 선보일 i20의 전기차 버전을 기다려야 할 것 같다고 해요.
2)
레오모터스 ‘전기 SUV’ 소리없이 강하다
기사입력 2008-08-18
지난 13일 서울시 독산동에 있는 전기차 제조사 레오모터스를 찾았다. 이 회사는 지난 2006년 출범 이후 전기경차와 전기스쿠터, 전기트럭 등을 잇따라 개발하면서 전기차 시장을 선도한다. 내년부터 국내에 시판할 도로주행용 전기차를 처음으로 타봤다.
이날 시승한 전기차는 젊은 층을 겨냥한 소형 SUV(모델명 S-15) 타입이다. S-15는 도요타의 인기 SUV모델인 ‘라브(RAV)4’의 플랫폼에 전동식 파워트레인(모터+트랜스미션)을 결합한 전기SUV 차량이다. 시판 중인 가솔린 자동차의 프레임과 바디, 내장재까지 그대로 가져왔기에 외형상으로 전기차란 사실이 전혀 드러나지 않는다. 요즘 저속형 전기차의 도로주행 여부를 놓고 법적 논란이 일지만 S-15는 안전성과 성능면에서 도로주행에 무리가 없는 국내 최초의 본격적인 전기차다.
본네트를 열어봤다. 엔진이 있을 자리가 휑하니 비었다. 작은 베개 만한 15Kw급 AC모터가 이 차를 움직이는 구동력의 전부다. 자동차 엔진룸에 빈 공간이 워낙 많아 충돌시 안전을 지켜주는 크러시존은 충분히 확보했다는 설명이다. 최대 1200번까지 충전이 가능한 신형 납축배터리는 차량 뒷 자리에 고정됐다.
내부 인테리어와 편의장치는 보급형 SUV모델로서 나무랄 데 없는 수준이다. 주행능력을 시험해 봤다. 시동키를 돌려도 시동 소리가 전혀 안 들린다. 모든 전기차의 장점인 정지상태에서 정숙함은 기존의 어떤 최고급 승용차도 못 따라올 수준이다. S-15는 5단 수동식 변속기를 달았지만 특이하게 클러치가 없다. 가속페달에서 발을 떼면 동력이 저절로 끊겨서 클러치 없이도 기어를 쉽게 바꿀 수 있다. 가속페달을 밟자 ‘쉬윙’ 하는 기계음과 함께 차가 앞으로 튀어나간다. 가속력이 장난이 아니다. 이 차를 끄는 15Kw모터는 사실 800cc경차 엔진수준이다. 차량덩치에 비하면 힘이 크게 달린다. 그 대신에 전기모터는 초기 토크가 좋아 1단 출발시 가속력은 2000cc급 엔진과 맞먹는다. 탁 트인 길로 들어섰다. 가속페달을 끝까지 밟아봤다. 역시 모터출력의 한계로 속도계는 80㎞/h를 넘지 못했다. 고속도로 진입은 어렵지만 시내주행에는 충분한 주행능력이다. 레오모터스는 보급형 S-15의 상위모델로 40Kw급 전기모터를 장착한 S-40모델도 개발 중이다. S-40은 제로백이 6초, 최고시속 150Km로 스포츠카와 맞먹는 주행성능을 갖춘다.
시승을 통해 전기차의 정숙함에 뒤따르는 단점도 나타났다. 엔진소음이 제로에 가깝다 보니 솔직히 운전의 재미가 떨어졌다. 실내가 너무 조용해 트랜스미션과 서스펜션의 삐걱거리는 소음이 신경을 건드렸다. 아직 개선할 점은 많다. 하지만 초고유가 시대에 전기차가 지닌 경제성과 친환경성은 너무도 매력적이다. 레오모터스는 안전성 평가를 거쳐 내년 하반기부터 S-15를 대당 2500만원에 판매할 예정이다. 석유가 바닥나도 계속 탈 수 있는 자동차가 있다는 게 얼마나 다행인가.
2.
MMSK는 16일 미쓰비시가 7월부터 일본에서 판매하는 아이미브를 국내에 가져왔지요.
미쓰비시 자동차를 국내 판매하는 MMSK가 그린카 시장에 뛰어든 토요타 및 현대·기아의
하이브리드카에 맞서기 위해 세계 최초로 양산된 4인승 전기차를 한국에 선보였지요.
최고 속도는 시속 130km이며, 최대출력은 64PS이고,
최대토크는 18.3kg.m이며, 이산화탄소 배출량은 제로이지요.
미쓰비시의 가솔린 경차 아이를 베이스로 만든 이 차는 전기모터와
석유엔진을 동력원을 사용하는 하이브리드카와 달리 전기모터만으로 운행되지요.
미쓰비씨모터스의 세계최초 양산 전기차 아이미브는
1회 충전으로 약 160km 주행이 가능하고 최고 속도는 130km라 거의 경차 정도 능력은 되지요.30일 기준으로 매일 충전 운행시 전기료는 10만원 가량 되고요. 4800km를 달릴 수 있죠.
충전시간은 일반 가정에서 한다고 가정시 7시간정도 걸린답니다.
도요타, 혼다에 비해서 하이브리드 기술이 뒤지던 미쓰비씨가 반격에 나선 것이죠 ㅎㅎ
닛산도 조만간 이와 같은 차량을 제작, 출시한다고 하더라고요.
0일 동안 매일 충전해 운행할 경우 약 10만으로 4800km를 운행할 수
있으며, 가솔린 기준으로 환산하면 1L 당 62km를 주행하는 셈이에요.
아이미브는 1회 충전으로 160km를 주행할 수 있고,
에어컨을 사용하면 130km 정도 달릴 수 있어요.
고속충전기로 80%를 충전하는 데 30분, 100% 충전하는 데 40분 정도 걸리며,
집에서 200V로 충전할 때는 80% 충전에 걸리는 시간이 7시간 이지요.
리튬 이온배터리를 사용하는 아이미브는 전용케이블을 통해 충전할 수 있지요
1)
전기모터 : 60kw (82hp), 26.5kg 최대토크, 80개의 battery cell,
최대속도 : 100km, max 160km
전기차는 주행성능을 지닌 손색없는 자동차라고 하는데요.
23일 있었던 시승식의 전기자동차는 기아의 1000cc경차 모델인
모닝의 전동식 파워트레인을 결합한 전기차량이라고 해요.
이번에 시승식을 갖은 모닝 전기차는 가솔린 가솔린 엔진을 떼어낸 자리에
무게 75kg의 최대출력 65kW급 수랭식 AC모터와 컨트롤러 박스를 달았으며
최대토크는 26.0kg.m로 미쓰비시 전기경차보다 높아서 순간 가속력이 더 낫다는데요.
배터리는 코캄이 제조한 30kWh급 리튬폴리머 파워팩을 뒷좌석에 장착했으며
차량의 외형과 인테리어, 편의장치는 시판 중인 모닝과 똑같다고 해요.
운전석 옆에 붙은 배터리 충전량 표시장치가 전기차의 정체성을 드러내는 유일한 표식인데요.첨단 자동차로서 뭔가 특별함을 원하는 운전자에겐 실망이겠지만
본래 전기 개조차는 평범함과 실용성이 특성인데요.
시동스위치를 올렸으며 낮은 기계음과 함께 파워브레이크에 철컥하고 압력이 들어차는 소리가 들린다네요.전기차의 정숙함은 일반 차량이라면 묻혀서 넘어갈 기계적 작동음까지 부각시키는 단점도 되는데요.시승차는 5단 수동식 변속기를 달았는데 전기모터의 토크 특성을 고려해서 2단 출발을 시도했다고 해요.
클러치 페달에서 슬쩍 발을 떼자 기계음과 함께 차량이 튀어나가며 제로백은 8초 후반으로 경차 수준을 훌쩍 넘어섰다는데요. 이것도 주행거리를 늘리기 위해 모터출력을 30% 가량 낮춰 놓았다고 해요.
가까운 중부고속도로에 진입하면서 가속페달을 끝까지 밟아봤을때 속도계는 120㎞/h를
쉽게 넘어섰다고 하는데요. 익숙한 엔진소리가 아니라 마치 제트기와 비슷한 소리가 난다고 해요.모닝 전기차는 경차샷시의 특성상 시속 130㎞/h를 넘지 않도록 세팅해놓았지만 시내주행은 물론 고속도로를 타기에 충분한 성능인데요.
핸들이 무겁고 차체반응이 둔한 점은 아쉬웠다네요.
연구소로 돌아와서 확인해보니 모닝 전기차는 배터리팩 무게 때문에 일반 모닝보다
중량이 210kg 더 늘었으며 성인 3명의 무게가 늘면서 경차 특유의 민첩한 조향성이 사라진 것인데요.
대신 강력한 전기 파워트레인 덕분에 고속주행능력은 훨씬 좋아졌고 운전특성을 고려할 때
복잡한 시내 주행보다는 수도권에서 서울로 통근하는 용도로 추천된다고 해요.
회사측은 모닝 전기차가 한번 충전으로 고속도로에서 180∼200㎞ 주행이 가능하며
모든 전기차는 파워를 높이면 배터리 소모가 심해지고 주행거리가 떨어진다는데요.
현재 전기모터, 배터리 기술수준을 고려할 때 모닝 전기차는 힘과
주행거리의 밸런스가 가장 적절하고 상용화에 근접해있다네요.
레오모터스는 모닝 전기차를 아직 시판할 계획이 없다고 하는데요.
거대 완성차업체가 장악한 글로벌 자동차 시장에 직접 뛰어드는 대신 전기파워트레인을 공급하는
핵심 부품업체로서 성장하겠다는 전략이라 일반 소비자들이 이같은 컨셉의 전기경차를 갖고 싶다면
내년에 현대차가 선보일 i20의 전기차 버전을 기다려야 할 것 같다고 해요.
2)
레오모터스 ‘전기 SUV’ 소리없이 강하다
기사입력 2008-08-18
지난 13일 서울시 독산동에 있는 전기차 제조사 레오모터스를 찾았다. 이 회사는 지난 2006년 출범 이후 전기경차와 전기스쿠터, 전기트럭 등을 잇따라 개발하면서 전기차 시장을 선도한다. 내년부터 국내에 시판할 도로주행용 전기차를 처음으로 타봤다.
이날 시승한 전기차는 젊은 층을 겨냥한 소형 SUV(모델명 S-15) 타입이다. S-15는 도요타의 인기 SUV모델인 ‘라브(RAV)4’의 플랫폼에 전동식 파워트레인(모터+트랜스미션)을 결합한 전기SUV 차량이다. 시판 중인 가솔린 자동차의 프레임과 바디, 내장재까지 그대로 가져왔기에 외형상으로 전기차란 사실이 전혀 드러나지 않는다. 요즘 저속형 전기차의 도로주행 여부를 놓고 법적 논란이 일지만 S-15는 안전성과 성능면에서 도로주행에 무리가 없는 국내 최초의 본격적인 전기차다.
본네트를 열어봤다. 엔진이 있을 자리가 휑하니 비었다. 작은 베개 만한 15Kw급 AC모터가 이 차를 움직이는 구동력의 전부다. 자동차 엔진룸에 빈 공간이 워낙 많아 충돌시 안전을 지켜주는 크러시존은 충분히 확보했다는 설명이다. 최대 1200번까지 충전이 가능한 신형 납축배터리는 차량 뒷 자리에 고정됐다.
내부 인테리어와 편의장치는 보급형 SUV모델로서 나무랄 데 없는 수준이다. 주행능력을 시험해 봤다. 시동키를 돌려도 시동 소리가 전혀 안 들린다. 모든 전기차의 장점인 정지상태에서 정숙함은 기존의 어떤 최고급 승용차도 못 따라올 수준이다. S-15는 5단 수동식 변속기를 달았지만 특이하게 클러치가 없다. 가속페달에서 발을 떼면 동력이 저절로 끊겨서 클러치 없이도 기어를 쉽게 바꿀 수 있다. 가속페달을 밟자 ‘쉬윙’ 하는 기계음과 함께 차가 앞으로 튀어나간다. 가속력이 장난이 아니다. 이 차를 끄는 15Kw모터는 사실 800cc경차 엔진수준이다. 차량덩치에 비하면 힘이 크게 달린다. 그 대신에 전기모터는 초기 토크가 좋아 1단 출발시 가속력은 2000cc급 엔진과 맞먹는다. 탁 트인 길로 들어섰다. 가속페달을 끝까지 밟아봤다. 역시 모터출력의 한계로 속도계는 80㎞/h를 넘지 못했다. 고속도로 진입은 어렵지만 시내주행에는 충분한 주행능력이다. 레오모터스는 보급형 S-15의 상위모델로 40Kw급 전기모터를 장착한 S-40모델도 개발 중이다. S-40은 제로백이 6초, 최고시속 150Km로 스포츠카와 맞먹는 주행성능을 갖춘다.
시승을 통해 전기차의 정숙함에 뒤따르는 단점도 나타났다. 엔진소음이 제로에 가깝다 보니 솔직히 운전의 재미가 떨어졌다. 실내가 너무 조용해 트랜스미션과 서스펜션의 삐걱거리는 소음이 신경을 건드렸다. 아직 개선할 점은 많다. 하지만 초고유가 시대에 전기차가 지닌 경제성과 친환경성은 너무도 매력적이다. 레오모터스는 안전성 평가를 거쳐 내년 하반기부터 S-15를 대당 2500만원에 판매할 예정이다. 석유가 바닥나도 계속 탈 수 있는 자동차가 있다는 게 얼마나 다행인가.
2.
MMSK는 16일 미쓰비시가 7월부터 일본에서 판매하는 아이미브를 국내에 가져왔지요.
미쓰비시 자동차를 국내 판매하는 MMSK가 그린카 시장에 뛰어든 토요타 및 현대·기아의
하이브리드카에 맞서기 위해 세계 최초로 양산된 4인승 전기차를 한국에 선보였지요.
최고 속도는 시속 130km이며, 최대출력은 64PS이고,
최대토크는 18.3kg.m이며, 이산화탄소 배출량은 제로이지요.
미쓰비시의 가솔린 경차 아이를 베이스로 만든 이 차는 전기모터와
석유엔진을 동력원을 사용하는 하이브리드카와 달리 전기모터만으로 운행되지요.
미쓰비씨모터스의 세계최초 양산 전기차 아이미브는
1회 충전으로 약 160km 주행이 가능하고 최고 속도는 130km라 거의 경차 정도 능력은 되지요.30일 기준으로 매일 충전 운행시 전기료는 10만원 가량 되고요. 4800km를 달릴 수 있죠.
충전시간은 일반 가정에서 한다고 가정시 7시간정도 걸린답니다.
도요타, 혼다에 비해서 하이브리드 기술이 뒤지던 미쓰비씨가 반격에 나선 것이죠 ㅎㅎ
닛산도 조만간 이와 같은 차량을 제작, 출시한다고 하더라고요.
0일 동안 매일 충전해 운행할 경우 약 10만으로 4800km를 운행할 수
있으며, 가솔린 기준으로 환산하면 1L 당 62km를 주행하는 셈이에요.
아이미브는 1회 충전으로 160km를 주행할 수 있고,
에어컨을 사용하면 130km 정도 달릴 수 있어요.
고속충전기로 80%를 충전하는 데 30분, 100% 충전하는 데 40분 정도 걸리며,
집에서 200V로 충전할 때는 80% 충전에 걸리는 시간이 7시간 이지요.
리튬 이온배터리를 사용하는 아이미브는 전용케이블을 통해 충전할 수 있지요
2009년 9월 11일 금요일
전기차 개조시 주요부품의 하나인 밧데리,밧데리콘트롤러(BMS)
전기차의 구성핵심은 모터(AC,DC), 전원인 밧데리(LiIon,LIFEPO등)와 BMS(Battery management system, cell board, CAN-BUS로 통신) 그리고 충전기로 구성된다. 그외 전기장치 부속품등이 기존 GAS 차량을 대체할 수 있다.
그리고 전기차의 대부분이 차량주요부품에서 발생하는 데이타를 집적할 수 있는 Data Logger기능이 필요하다.
참고할 사이트로서 배터리 제조업체인 업체의 home page를 참고하기 바랍니다.
http://liionbms.com/php/faq.php#Logger
참고적으로 밧데리 충전기를 판매하고 있는데, 미국에서 $350정도한다.
Chargers for large battery packs with CAN bus
Low-cost, CAN Bus, PFC charger for large battery packs
********* AVAILABLE ONLY IN THE USA ***************
Elithion has developed a low-cost, CAN Bus, PFC (Power Factor Corrected) charger for large battery packs, which is simple to install and operate.
Charger block diagram
Charger block diagram
back to topDescription
* Significantly less expensive than other traction battery chargers on the market
* Power Factor Corrected (PFC) input
* Non-isolated
* Fan cooled
* Regulation: Input AC current or Max output DC voltage, whichever is limiting
* Fuse protected: reverse battery polarity, output short, short to chassis
* Control: closed contact or CAN Bus
* Monitoring: CAN Bus
* Mandated regulatory testing: FCC Part 15 tested
* Optional regulatory testing (UL, CSA, CE...): may be performed by end user
back to topSpecifications
* Electrical:
o Minimum battery voltage (at discharged battery): 190 Vdc
o Maximum battery voltage (at fully charged battery): adjustable from 200 to 450 Vdc
o Input current: 15 Aac, user adjustable down to 1 Aac
o Max power (at 120 Vac): 1800 W
o Efficiency: > 95 %
o Power factor: > 0.99
o Charge current shape: fully rectified sine wave
o Optional 13.5 V, 1A output to float charge 12 V lead-acid auxiliary battery
Molex Mini-Fit Jr 6-pin connector Anderson 15 A connectors IEC power entry connector
* Connectors:
o AC input connector: IEC 320-C14
o DC output connector: Anderson 15 A powerpole
o Control connector: 6-pin Molex Mini-fit JR connector: Common, 12 V, control
1. gnd
2. CAN-lo
3. CAN-hi
4. control in (closed contact to GND = on, open contact (1 kOhm pull-up to +12V) = off
5. n.c.
6. 12 V out, 1 A
* Adjustments:
o User adjustment: AC input current (0 to 15 A)
o Internal adjustment: Max DC out voltage (200 to 450 V)
* Mechanical and environmental:
o Temperature range: -20 to +80 °C
o Dimensions: 3" x 5" x 7"
back to topPrices and availability
Price: US$ 350, if ordered as part of a system. Else, a "volume compensating fee" applies
Available only in the USA.
Availability, typical: 2 weeks from receipt of order
e-logo
그리고 전기차의 대부분이 차량주요부품에서 발생하는 데이타를 집적할 수 있는 Data Logger기능이 필요하다.
참고할 사이트로서 배터리 제조업체인 업체의 home page를 참고하기 바랍니다.
http://liionbms.com/php/faq.php#Logger
참고적으로 밧데리 충전기를 판매하고 있는데, 미국에서 $350정도한다.
Chargers for large battery packs with CAN bus
Low-cost, CAN Bus, PFC charger for large battery packs
********* AVAILABLE ONLY IN THE USA ***************
Elithion has developed a low-cost, CAN Bus, PFC (Power Factor Corrected) charger for large battery packs, which is simple to install and operate.
Charger block diagram
Charger block diagram
back to topDescription
* Significantly less expensive than other traction battery chargers on the market
* Power Factor Corrected (PFC) input
* Non-isolated
* Fan cooled
* Regulation: Input AC current or Max output DC voltage, whichever is limiting
* Fuse protected: reverse battery polarity, output short, short to chassis
* Control: closed contact or CAN Bus
* Monitoring: CAN Bus
* Mandated regulatory testing: FCC Part 15 tested
* Optional regulatory testing (UL, CSA, CE...): may be performed by end user
back to topSpecifications
* Electrical:
o Minimum battery voltage (at discharged battery): 190 Vdc
o Maximum battery voltage (at fully charged battery): adjustable from 200 to 450 Vdc
o Input current: 15 Aac, user adjustable down to 1 Aac
o Max power (at 120 Vac): 1800 W
o Efficiency: > 95 %
o Power factor: > 0.99
o Charge current shape: fully rectified sine wave
o Optional 13.5 V, 1A output to float charge 12 V lead-acid auxiliary battery
Molex Mini-Fit Jr 6-pin connector Anderson 15 A connectors IEC power entry connector
* Connectors:
o AC input connector: IEC 320-C14
o DC output connector: Anderson 15 A powerpole
o Control connector: 6-pin Molex Mini-fit JR connector: Common, 12 V, control
1. gnd
2. CAN-lo
3. CAN-hi
4. control in (closed contact to GND = on, open contact (1 kOhm pull-up to +12V) = off
5. n.c.
6. 12 V out, 1 A
* Adjustments:
o User adjustment: AC input current (0 to 15 A)
o Internal adjustment: Max DC out voltage (200 to 450 V)
* Mechanical and environmental:
o Temperature range: -20 to +80 °C
o Dimensions: 3" x 5" x 7"
back to topPrices and availability
Price: US$ 350, if ordered as part of a system. Else, a "volume compensating fee" applies
Available only in the USA.
Availability, typical: 2 weeks from receipt of order
e-logo
2009년 9월 10일 목요일
DIY Advanced High Performance EV conversion Project.미국 EV 전문가의 글
http://metricmind.com/ac_honda/main2.htm
On the following pages I will describe the process of converting a gasoline car to electric one. More precisely, upgrading, because I've converted it to the electric already back in 1995, but since now just about every single component of existing EV is doing to be replaced, it's almost like starting from scratch. Empty engine compartment, new battery boxes, etc.
You will not find here a flashy Macromedia presentations or fancy Java animations, the web site is designed simple and to load quickly. What you will find is fairly detailed steps taken toward my goal and technical details actually useful to someone who wants to use my experience. Anticipating usual questions, wherever possible, I will provide information on the supplier or the hardware or the service I used, and the cost.
This EV is my long time passionate project and the test bed for different hardware, and as such - never really ending. Countless hours of the labor of love are put in, the car's floor body was cut out and re-welded a few times to accommodate improvements and upgrades. Every time this is done, I realize how I should have done it in the first place so that upgrade would not be so painful. Yet, it's hardly possible to predict all possible changes in future. How could I have known that DC motor is going to be replaced with AC one, PWM controller - with AC inverter, system will come back to water cooling, 10 LEad acid batteries will be replaced with 28 ones, later - with 96 LiIon ones (later supplemented with ultracapacitor bank) and then - with 24 NiMH ones?? I still don't know what the future holds. As long as the body can handle modifications I will keep making them, that's the fun part. To me the conversion and creation process is just as exciting as the outcome.
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The plans are to built more advanced vehicle than an average EVer today would build. No secret that usually EV driven on the highway has to squeeze out near maximum performance to keep up with the traffic. Rarely a common EV speed can exceed 100 mph which is no problem for modern ICE cars. More importantly, at 55...65 mph further acceleration of an EV usually is not as good as that of the ICE counterpart. To merge into highway traffic from the ramp I always had to floor the accelerator pedal and wish I had 20-30 more hp available at the moment...
So my hope is that current major upgrade will make my Honda perform better than it was before conversion. To achieve it with reasonable budget careful planning should take place. To satisfy your curiosity about Siemens AC drive systems (I used one here) , they are available for purchase, please visit Metric Mind Engineering web site for details. For the energy storage NiMH batteries are there for now; once the BMS (battery management system) will be completed, LiIon or LiPoly traction pack is going to be installed.
I have read somewhere that along Hwy I-101 and I-5 in the bay area in California the brake pads dust is considered the second largest source of the environmental pollution. WEll, if true, an EV in that respect is no better than comparable ICE vehicle - you must brake just as often, don't you?. EVs might be zero emission vehicles, but not zero pollution vehicles. Well, with AC drive with regenerative braking I am able to reduce that kind of pollution as well, reducing my impact on the environment even further! In fact, once in a while I disable regen just to clean rust off the brake disks because regen allows complete stop and usually mechanical brakes are not used at all (other than keep the car still).
And lastly, if you think that EVs are not truly zero emission vehicles, and just move pollution from the tail pipe to remote electricity generation plant, I have news for you - this is BIG MISCONCEPTION and is what oil companies and auto manufacturers want you to believe in. Why would they do that? Simple money talk. They want you keep buying gasoline, and keep coming back to them for maintenance of increasingly complex modern cars, making them richer. That's why they scared to death of EVs and that's why you won't see EV ads in main stream media. But this is totally other subject and I won't discuss it here. I'll just say that aside the fact that electricity can (and being) generated from 100% renewable sources like hydro, wind, geothermal, solar (or nuclear), even if coal is used, it is by far the cleanest source of energy compare to any modern car. Not convinced? Download some reading (PDF format), and think about it.
--------------------------------------------------------------------------------
In a perfect world everyone would drive an EV.
Until then, be among those who brings that future a little closer.
I sincerely wish you luck with your adventure and hope to see you on the road
On the following pages I will describe the process of converting a gasoline car to electric one. More precisely, upgrading, because I've converted it to the electric already back in 1995, but since now just about every single component of existing EV is doing to be replaced, it's almost like starting from scratch. Empty engine compartment, new battery boxes, etc.
You will not find here a flashy Macromedia presentations or fancy Java animations, the web site is designed simple and to load quickly. What you will find is fairly detailed steps taken toward my goal and technical details actually useful to someone who wants to use my experience. Anticipating usual questions, wherever possible, I will provide information on the supplier or the hardware or the service I used, and the cost.
This EV is my long time passionate project and the test bed for different hardware, and as such - never really ending. Countless hours of the labor of love are put in, the car's floor body was cut out and re-welded a few times to accommodate improvements and upgrades. Every time this is done, I realize how I should have done it in the first place so that upgrade would not be so painful. Yet, it's hardly possible to predict all possible changes in future. How could I have known that DC motor is going to be replaced with AC one, PWM controller - with AC inverter, system will come back to water cooling, 10 LEad acid batteries will be replaced with 28 ones, later - with 96 LiIon ones (later supplemented with ultracapacitor bank) and then - with 24 NiMH ones?? I still don't know what the future holds. As long as the body can handle modifications I will keep making them, that's the fun part. To me the conversion and creation process is just as exciting as the outcome.
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The plans are to built more advanced vehicle than an average EVer today would build. No secret that usually EV driven on the highway has to squeeze out near maximum performance to keep up with the traffic. Rarely a common EV speed can exceed 100 mph which is no problem for modern ICE cars. More importantly, at 55...65 mph further acceleration of an EV usually is not as good as that of the ICE counterpart. To merge into highway traffic from the ramp I always had to floor the accelerator pedal and wish I had 20-30 more hp available at the moment...
So my hope is that current major upgrade will make my Honda perform better than it was before conversion. To achieve it with reasonable budget careful planning should take place. To satisfy your curiosity about Siemens AC drive systems (I used one here) , they are available for purchase, please visit Metric Mind Engineering web site for details. For the energy storage NiMH batteries are there for now; once the BMS (battery management system) will be completed, LiIon or LiPoly traction pack is going to be installed.
I have read somewhere that along Hwy I-101 and I-5 in the bay area in California the brake pads dust is considered the second largest source of the environmental pollution. WEll, if true, an EV in that respect is no better than comparable ICE vehicle - you must brake just as often, don't you?. EVs might be zero emission vehicles, but not zero pollution vehicles. Well, with AC drive with regenerative braking I am able to reduce that kind of pollution as well, reducing my impact on the environment even further! In fact, once in a while I disable regen just to clean rust off the brake disks because regen allows complete stop and usually mechanical brakes are not used at all (other than keep the car still).
And lastly, if you think that EVs are not truly zero emission vehicles, and just move pollution from the tail pipe to remote electricity generation plant, I have news for you - this is BIG MISCONCEPTION and is what oil companies and auto manufacturers want you to believe in. Why would they do that? Simple money talk. They want you keep buying gasoline, and keep coming back to them for maintenance of increasingly complex modern cars, making them richer. That's why they scared to death of EVs and that's why you won't see EV ads in main stream media. But this is totally other subject and I won't discuss it here. I'll just say that aside the fact that electricity can (and being) generated from 100% renewable sources like hydro, wind, geothermal, solar (or nuclear), even if coal is used, it is by far the cleanest source of energy compare to any modern car. Not convinced? Download some reading (PDF format), and think about it.
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In a perfect world everyone would drive an EV.
Until then, be among those who brings that future a little closer.
I sincerely wish you luck with your adventure and hope to see you on the road
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