"daytripper" wrote in message
...
On Tue, 8 Jun 2004 21:17:33 -0400, "Marty S."
wrote:

I'm running 2 12-volt batteries running in series to power my 24-volt
electric motor in my jon boat (on an electric-only reservoir) and I
want to
run a fish finder. Here's my question -- can I safely run the fish
finder
off of one of the 2 12-volt batteries while running the 24-volt
motor? Or,
is that going to burn up the fish finder? Should I just invest in a
couple
of 6-volt lantern batteries instead?

One of the batteries is referenced to GROUND, the other is not.

If you connect your fish finder across the battery that is referenced
to
GROUND, you should be fine. If you make the mistake of connecting
across the
*other* battery, what the fish finder "thinks" is GROUND will actually
be 12
volts *above* GROUND, which sooner or later will be revealed to be A
Bad
Thing...

/daytripper

Near as I can tell in my boat, neither side of the batteries for the
trolling motor is ground. The trolling motor basically floats. So go
ahead. use the battery connected to ground if one of them is connected
to ground.

del cecchi.