Dead Trolling Battery

Need your suggestions. I have a interstate battery in my tracker that normally lets me troll for 7-8 hours before it runs out of juice. Am using a digital motor guide trolling motor, 12v system, same for past two years. Last two times out battery was dead in less than three hours. Thought maybe battery was bad, bench charged it over night and had it tested twice today, both times said was putting out more than it is rated at, and is still good. Have been using the on board charger that came with the boat until last night. Now I'm not sure if it's the charger, or if the trolling motor is now drawing more current than before. Have made no changes to any wiring, or added anything new. Any thoughts?

don't know if i am right maybe someone else on here will chime in i'm sure but ,
the deep cycle batterys do have a limit on the number of times they can be recharged not that they just wont go but the run time will keep getting shorter and shorter.
and it's hard to check voltage on a deep cycle for the reason that they hold 12 volts til dead unlike say a car starting battery that drops voltage as it goes dead .
and maybe like you said it very well could be your charger . hope someone with more knowledge jumps in here and either supports me or tells me i'm wrong and tells you right lol.
.

hope i helped just my experiance ,
Scott

Run two batteries in parallel for your 12v motor, I just started doing it about a month ago and wish I had done it years ago. I have trolled from daylight till dark, get home, put it on the charger and still have 3/4 of battery left.

There is no easy way to test a deep-cycle. They get smaller everytime you use them.

How old is the battery?

I'm already in the process of setting that up. will put the second battery in one of my rear storage boxes, and run wires over to the first battery under the rear cover. Already dug out the foam over to the sheet metal, just have to drill the hole and run the wires. I just don't want to miss anything that may have a simple answer.

Am at 28 mo's on a 30 mo battery, that's why the battery was my first thought. The change happened rapidly though. trolled 7 hours on it couple times last week, now down to less than 3.

Test your charger by checking the voltage at the battery with the charger off, then plug it in and check again. You should see over 13V with the charger on.

Have you checked the fluid levels lately? I had a walmart battery that was doing that and found that the fluid level was really low. Filled it with DISTILLED water and charged it over night and it's good as new now.

Yes, have checked the fluid level which is fine. Have only had to add a small amount of water to it and that was last year. Just seemed odd to me that the power dropped off so rapidly from what it was a week ago.

Ok...so you are saying that I can wire another battery to my trolling motor battery, just leave my trolling motor hooked up to that battery and it will give me "more time", "more charge"? I never knew that. But, what if my other battery is what all my accessories are on...will it hurt anything there (fishfinders, bilge, running lights, interior lights)? Just wondering. If this works, it would definitely give me a HUGE peace of mind.

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Originally Posted by mrwillis

Ok...so you are saying that I can wire another battery to my trolling motor battery, just leave my trolling motor hooked up to that battery and it will give me "more time", "more charge"? I never knew that. But, what if my other battery is what all my accessories are on...will it hurt anything there (fishfinders, bilge, running lights, interior lights)? Just wondering. If this works, it would definitely give me a HUGE peace of mind.

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Won't hurt a thing. Just connect them in parallel.

I am having the same problem with a walmart battery,took it to get it tested and they said it was good,but not getting near as much time as used to,added another bat in series,helped me get more trolling but still wondering about the walmart battery.

You need to load test the battery.

It was load tested and they said it was good,but I dont think so

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