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?
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.