Quote:
Originally Posted by Qbranch
First off, what battery technology is the best? The most economical? Longest Lasting? I hear NiMH is good, but whats your say?
|
With batteries, weight is your biggest enemy. Keeping that in mind, I'd go with the Lithium-based battery trend that all consumer electronics have been going with as of late, as they are among the lighest of batteries.
Quote:
Originally Posted by Qbranch
What kind of transmission? Leave the auto in and find a motor with a torque curve to match? Manual tranny electrically actuated? CVT?
|
Chances are, you probably won't need a traditional car transmission if you are using electric motors. Internal combustion engines develop their highest torque at high RPMs, and the highest torque in a car is needed when you first get it moving (e.g. slow RPM). That is why you need transmissions in a car with 3, 4, 5, or 6 gears.
With an electric motor however, you get your highest torque at zero RPM, which is perfectly suited for getting the car rolling. In an electric car, you probably won't need anything more complicated that a 2-speed transmission, if that. (The
Tesla Roadster only has a two speed transmission, however it can run entirely in second-gear if the driver wants.)
Also, you'd get much better results if you use 4 small electric motors (one driving each wheel), than one giant one going through an auto/manual transmissions, differentials, etc. Most modern electric trains no longer have traditional locomotive units, but rather powered wheelsets spread along the length of the train, as this helps with the weight distribution and efficiency of the total system.
You can also use the motors for regenerative dynamic braking, however you'll still need traditional brakes. (Once you get below a certain speed, dynamic braking will stop generating enough electricity to recharge any batteries/capacitors, so you'll need traditional brakes to completely stop.)