Fish-Hawk.Net

Hey Guys, my dads boat has been having issues with his trolling motor battery life since last year. After about two hours of solid use, they lose power, to the point of turning off power to the Ulterra. The batteries are about 5 years old and are gel type. I don't know the amp hours off hand, but they are monsters, had to grind down the battery tray to fit them in.

I've charged them with the on board charger, and my genius charger a separate time, which should throw an error if they are bad. I have used a resistive load tester on them 3 separate times and the reading shows they are good.

I'm wondering if this may be a result of some sort of temporary shorting between the batteries and motor, some sort of overload or fuse, or an issue with the Ulterra itself.

Any insight would be greatly appreciated.

5 years is a good amount of time for batteries, that is usually around the time I end up replacing mine.

Have you testes the batteries with a voltmeter when the motor turns off? Do you know the gauge of wiring in the boat and how long it is? Have you found where the fuse/breaker is?

My Breaker needs to be manually reset but I do believe there are a few that reset themselves after a bit of cooling.

Take the batteries out, charge them up and stop by Total Battery or Magnacharge and have them test them.

Not sure if you figured out your battery issues but 3 years is about the life span of lead acid batteries, 5 years on gel and AGM batteries and 10 years on lithiums. I would suspect that they've reached the end of their life span.

How did it go?