I'd strongly recommend against cranking (car) batteries. It's not a question
of how long the batteries will last while in use, it's a question of how the
battery holds a charge. Cranking batteries are designed to deliver quick and
momentary power. They are also designed to be kept fully charged. If this
battery was drained and recharged several times it will stop holding a
charge and probably only last a few month. A deep cycle battery is designed
for this type of charge and discharge and can last years.

"Joseph Stachyra" wrote in message
...
Dear Marty: You say weight is a problem, and you say your use is only
your local reservoir.
and your boat is very small, thus meaning, your not going into deep or
far
away waters.

1. response Car Batteries are lighter than deep cycle and cheaper, why