Plug-in Hybrid for Extreme Range

by Jason
(Sandy, OR, US)

Why doesn't anyone try to run their EV motor with power supplied from an alternator/power generator?

Hi, Jason -

They do.

Here's an interview with Alain St Yves in the Montreal area who built his own plug-in hybrid. The generator extends the range of his electric car when he wants it, and because he can take the generator out and leave it home, or turn it off while he's driving through Montreal, he has a lot of flexibility with his design.

If you're asking why they don't run the motor directly from the generator and leave out the batteries?

Because the electric motor draws a lot of power in the 0-45 acceleration or to go up hills. Generators are gas engines, and they run at a constant speed.

People use batteries to make sure the electric motor has all the juice it wants for peppy acceleration, and then use the gas engine to stuff the electrons back into the battery as they drive.

The (series wound DC) electric motor has more low-end torque, the gas engine takes a while to wind up, and you'd need a bigger gas engine than your typical generator in order to get the low-end acceleration you need to move a car along briskly.

I'm guessing - I don't know, I've never done it - that, even if you used a throttle or whatever to control the speed of the gas engine, a car with a gas engine directly powering an electric motor would be a bit of a slug, particularly at low speeds.


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But what about....
by: Logan

But what if you could replace the entire battery pack with a power supply delivering a constant voltage (say 144v) and a constant current, like 400-600 amps?

Range Extender
by: Patrick

Ben Nelson of has made a propane range extender for his Geo Metro conversion.

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