Daytripper: I don't have two motors. This is just a small jon boat powered
by an 24-volt electric trolling motor with 2 batteries connected in series.

--
Marty S.
Baltimore, MD USA


"daytripper" wrote in message
...
On Tue, 8 Jun 2004 22:55:51 -0400, "Marty S." wrote:

I'm not sure about your answer, Daytripper. I don't have either battery
connected to ground as far as I know. The + terminal of one battery goes
to
the motor, and the - terminal of the other battery goes to the motor, and
the other terminals are connected to each other so the battery is
connected
in series.

Might help to draw this out.

A typical 12v wiring job on a boat with an electric starter (at least),
some
part of the motor is connected to the negative pole of the 12v battery.
That
would be the moral equivalent to "earth ground" on a boat.

The electronics are referenced to the same potential, and things like
antenna
ground and lighting fixtures may be referenced to that same potential, as
it
is the return path for all powered things on the boat.

Shifting that potential by connecting the negative pole of the original
battery to the positive pole of the first battery (and then connecting the
negative pole of the second battery to the negative terminal of the
trolling
motor) runs a certain risk different current return paths at different
potentials coming in contact with each other. Ie: if the exterior of the
trolling motor is connected to its negative terminal, when the motor is in
the
water there could be current flowing through the *boat* motor (which is
connected to the negative pole of the original battery).

That wouldn't be good, I suspect ;-)

/daytripper