I have a 3 battery set up with a Minn Kota 330D charger in my boat. 2 Trolling motor batteries and one Cranking battery. The only thing running off my trolling motor batteries is the trolling motor. Everything else runs off the cranking battery. I unplug
the trolling motor when i back in the garage so it doesn't have anything drawing from it. When i charge the batteries they all get full, then within a week i would guess the trolling motor batteries are below 50% and take a couple hours to charge again. The cranking battery is down some as well but not as much as the trolling motor batteries even though it has a radio and fish finders plugged in. The cranking battery is 4 years old, the trolling motor batteries are only 2 years old. What is draining my trolling motor batteries down? Could the cranking battery some how be going bad and drawing power from the trolling motor batteries thru the charger some how? I charged them last night and unplugged them at full charge. this morning the Cranking battery showed 12.49 volts and the trolling motor batteries showed 12.8 volts although they were down already according to the charger. This is driving me nuts, i would love some opinions on what you guys think might be happening.
thanks in advance,
travis