Generally speaking, the alternators on outboards are NOT strong enough to
recharge a discharged trolling motor battery in any kind of normal
timeframe... yes, it can replenish the trolling battery somewhat, but I
believe you should factor in a battery charger fot topping off after the
fishing trip.

Delaware Jim.
"Dazed and Confuzed" wrote in message
...
John wrote:

"me" wrote in message
...
You were all such great help when I built my kayak and canoe, I
thought
someone might be able to help me on this. I bought a small 16 foot
boat
last month with a 60 4 stroke Yamaha and wanted to install a 12 volt
trolling motor for fishing. My question is, should I install a
seperate
deep cell battery for the trolling motor and charge it when I'm done
fishing, or replace the battery that's on the boat with two deep
cells. I
figured the motor would recharge the batteries but I wasn't sure if
they
could handle starting the motor, running the trolling motor, bilge,
lights,
and my son's Game Boy. And would the motor be able to recharge both
batteries. Any suggestions or opinions?

I'm not sure if you'll really need a seperate trolling motor. Why not
try fishing without it at least a few times first, then, if you really
need it, OK, buy one.

But, if you really feel you need a trolling motor, I would go with two
batteries and a battery switch. Set the switch to one of the battery
positions (battery 1 or battery 2, not the both position)when using
the trolling motor and, when you run the outboard, set it to the both
position. This way, when running the trolling motor, worst case, you
run the one battery until it's dead, then you just flip the switch to
the other battery position and you can still start the outboard with
the other battery. By switching to the both position when running the
outboard you can charge both batteries.

or use a "battery isolator" from JC whitney. About 70 bucks. One charge
circuit, two discharge
circuits. I think it is just a couple of diodes in a large heatsink, but
they DO work...


--

A friend is someone who knows you, understands the essential conflicts in
your thinking, in your
morals, and in your philosophy, and like you anyway.