That just means a few more batteries. What would be a good DC source voltage?
My comment about voltage was in response to what mxslick posted in post #17.
Don't see why it (120V) wouldn't. I think all VFD's take the incoming AC and rectify it to DC for the inverter bus anyways.
He's right about the rectifier of course. My point was that standard inverters generally wouldn't work at 120V.
That said, the drive system for an EV is not a typical standard VFD.
We have done a few with both brushed and brushless motors and battery voltages ranged from a nominal 48Vdc to 300Vdc. One of the limitations of a lower voltage battery is that everything has to cope with higher currents. Including the charger. Charging a 48V, 30kWh battery in five hours or so would need a 125A charger.
I think most of the EVs currently in production have a battery pack that is in the few hundreds of volts. The Tesla Roadster has a 375V, 53kWh battery - weighing in at 450kg or nearly half a ton.