Battery issues

This morning I headed out fishing and everything was fine, after a while my battery seemed to be drained but felt awfully quick for it to drain that fast. I took it in and charged it. Battery gauge said 100 so I went back out. As soon as I put my trolling motor in for 5 seconds it was back to 0. Went home put a new battery in and was fully charged went out and once again after using it for 5 seconds it was shot. Not sure what the problem is but battery 2 always seems to be 100 charged but the other battery seems to always get shot no matter even if you have a new battery in. Any ideas?

I’m kind of confused, but it Sounds like it’s not a battery issue. Sounds like an issue with the trolling motor, sounds like the brushes on the lower unit of the trolling motor are going bad. If it’s reading over 12v with a multimeter it’s the trolling motor. If not, it’s the battery. Easiest way to tell is hook it up to a multimeter or take it to an auto parts store and they can hook it up to a battery tester.

Well now after charging all night ones at 50 and 100 took it out and there instantly shot

If water levels are good and it won’t charge, most likely a bad cell. I too was confused by a battery issue this Spring when the battery would fully charge but then not start my main motor. The battery was able to charge at that point but was failing under load.

I have a battery ?

I set my Humminbird “low voltage” alarm at 11 volts cause I read that 10.5 volts was the minimum for the motor to crank.

The other day we were out fishing, anchored for about 3 hrs. I had the livewell on “Auto”. Also had the stereo & Humminbird on too.

At about the 3 hr mark we pull anchor and I start the big motor and get a low voltage alarm.

I am wondering if that means I need a bigger, newer battery …. or is that normal?

If I run the boat a while, the voltage gets back up over 13.5 volts without a problem.

The battery is 3 yrs old and everything is run back to the starting battery except for the trolling motor, which is all on its own battery.

I top off the battery cells with distilled water and store my batteries in the basement over the winter, on a trickle charger.

Turns out it was some bad circuit boards