EVs use a reasonably common set of parts. There's always a motor to move the car, a controller to regulate the speed, and batteries to provide the power.
Roughly, the choice of batteries decides how fast your car will go, and the controller determines how quickly it will get there. Any motor capable of handling your battery and controller configuration will work, although some are more efficient, or more capable of withstanding abuse.
Before Nathan left for Reno, we knew we wanted a common configuration: 144 volts of sealed AGM batteries, a 500 amp or better controller, and the reasonably-common Advanced DC 9" motor. Even in a big car, we knew that would give us the performance we specified in The Requirements. We also wanted instrumentation, a heater, and other items that were technically non-essential, but required in a practical sense.
We found a guy in Texas who had advertised all the parts we needed for cheap. Not only did his kit have a 600 amp controller, it also included instrumentation, a heater, and assorted hardware we'd need (like relays). All for $2500.
My wife (rightly) refused to spend that kind of money without some guarantee of getting what we paid for. Unfortunately, the seller refused to enter into an escrow agreement, no matter how easy I made it. He called it "crazy". (Now, really. How long has escrow been around? And for just this kind of problem, too.) My wife pointed out that it would be crazy for us to spend that much money blindly. When the seller recommended I call City Hall to get recommendations, we decided to let the deal drop.
I mean, really, I can't trust him, so I'm going to trust a politician?!?
