Both Minnkota and Motor Guide produce electric trolling motors big
enough to use as auxiliaries on small sailboats. Has anyone tried
running these motors as generators to charge the on-board batteries?
Does anyone know the motor configuration (permanent magnet, shunt wound,
series wound)?

BS

I had a Minnkota that I used on my dinghy. When we were properly anchored,
we launched the dinghy to go ashore and put the little Minnkota on, hooked
up a 40 amp/hr battery and off we went. Worked great, however, a word to the
wise:
The Minnkota model we had was a 39 amp/hr motor and the battery was a 40
amp/hr battery (the lightest, and cheapest, we could get) so a little math,
and presto - you got about an hour of motoring in that dinghy (there were 5
power settings and we NEVER used #5).
Your own usage may vary.


"Bob S" wrote in message
...
Both Minnkota and Motor Guide produce electric trolling motors big enough
to use as auxiliaries on small sailboats. Has anyone tried running these
motors as generators to charge the on-board batteries? Does anyone know
the motor configuration (permanent magnet, shunt wound, series wound)?

BS

I took mine apart to see what makes it tick. It is basically a permanent
magnet motor with "speed coils" used to limit the amount of power
getting to the motor to control speed. At the highest setting the
battery is connected directly to the motor. If you spin the motor (like
with an electric drill, the voltage at its terminals increases with
speed. The question now is "can it be spun fast enough under sail power
to get high enough output to charge the battery?"

BS

Bob S wrote:
Both Minnkota and Motor Guide produce electric trolling motors big
enough to use as auxiliaries on small sailboats. Has anyone tried
running these motors as generators to charge the on-board batteries?
Does anyone know the motor configuration (permanent magnet, shunt wound,
series wound)?

BS

Jim Campbell at eCanoe is the most informed source out there for trolling
motors. He's an electrical engineer who holds a patent for trolling motor
innovations. He's a nice guy and very helpful when asked serious, concise
questions.

http://www.ecanoe.org/

Bill Longyard



"Bob S" wrote in message
...
Both Minnkota and Motor Guide produce electric trolling motors big enough
to use as auxiliaries on small sailboats. Has anyone tried running these
motors as generators to charge the on-board batteries? Does anyone know
the motor configuration (permanent magnet, shunt wound, series wound)?

BS

Thanks, Bill. I'll give the url a try. I did take one of my motors
apart. It is a permanent magnet motor with "speed coils" inserted in
series with the motor as resistors to vary the speed. I'm also an
electrical engineer, BTW. The motor does generate when run in reverse
with a hand drill. Question now is whether towing it under sail will
generate enough to charge a battery. At 1100 rpm it put out over 5 volts.

BS

William Longyard wrote:
Jim Campbell at eCanoe is the most informed source out there for trolling
motors. He's an electrical engineer who holds a patent for trolling motor
innovations. He's a nice guy and very helpful when asked serious, concise
questions.

http://www.ecanoe.org/

Bill Longyard



"Bob S" wrote in message
...
Both Minnkota and Motor Guide produce electric trolling motors big enough
to use as auxiliaries on small sailboats. Has anyone tried running these
motors as generators to charge the on-board batteries? Does anyone know
the motor configuration (permanent magnet, shunt wound, series wound)?

BS