alt.energy.renewable

First, I am not an engineer, a designer or a mathematician. So
please, assume that I need hand-holding insofar as technical
information goes.
What would happen if you hooked a fractional horsepower motor to a
automobile generator, and fed the power into a bank of 12V deep-cycle
batteries? Think a brush whacker or rototiller motor, and gearing
appropriate for running the generator at optimal speed. The body of
the vehicle this system would be installed in would be a foam
fiberglass sandwich a la Riley on a square tubing frame, the electric
motor that sends it down the road could be direct drive, or run
through a motorcycle transmission, driving a single wheel. A tadpole
layout seems to be the most stable, and I think I would prefer it.
Finally, I have read something about rewiring 120V AC motors to 12V
DC, giving a wealth of available low-cost motors from washing
machines, etc. Is this feasible, wise or appropriate?
If these questions have been asked and answered before, please excuse
me. I searched but without success.