Re: (ET) Converting a gasoline lawnmower

[Jim Coate <jbc coate org>]

John de Rivaz wrote:
> Anyone any suggestions on converting a gasoline lawnmower to electric
> battery operation?

I think you'll find that DC is the only practical choice at the moment.
Although AC motors are easy enough to come by, a matching controller
(inverter) isn't so easy to find. Curtis makes plenty of DC controllers
in the size you'd be looking at. Or use a contactor controller (similar
to the Elec-Trak), or as someone else suggested just run at a constant
speed and use the original transmission to vary propulsion speed.

Electric motors can easily produce well over their continuos HP rating
for short periods, up to say 10 times for a brief pulse. My electric
pickup has a motor rated at 28 HP, I regularly pull 50-75 HP out of it
and can hit a theoretical 100 HP max that is limited by my batteries
rather than the motor itself.

If the goal is to get it up and running and mowing grass this summer,
I'd be inclined to keep as much of the original equipment in place as
possible and just bolt on a single motor to replace the gas engine. If
you want a great educational experience over the next year or so, then
I'd get into multiple motors and designing/building custom AC
controllers etc.

Have fun!
_________
Jim Coate
1992 Chevy S-10
1970s Elec-Trak E20
http://www.eeevee.com