Batteries in my boat

[Scoot]

I think I've got a trolling motor battery problem, but I'm not sure. My trolling motor batteries don't seem to have the "snoose" they did a year ago and don't seem to hold their charge as well as they should. I brought them in and had them tested and both tested fine. They are 2011 batteries. When they are all charged up, the voltmeter says they are at 12.65 volts. When I plug the charger (Minnkota 3 bank) in they are 13.4 volts (this is when the battery charger lights are blinking indicating it's charging). When the battery charger lights quit charging and the lights are on solid (i.e., not blinking), they test out at 12.65 volts.

In my mind, that all seems just fine. However, I just don't get the oomph from my trolling motor battery I think I should and it doesn't last as long as it should.

Thoughts?

[h8go4s]

Are all the connections clean, including the motor plug if it has one?

[Scoot]

H8go4s, I'm sure the battery connections are good, but I'm not sure about the plug. I'll double check that tonight.

[BoxMN]

It almost sounds like it is only running on one battery. We have had that happen in the past, and it was connections in the factory "12/24 v" wiring. We unhooked the factory, and ran our own strictly 24v wiring with 8 gauge wire and as direct as possible - two wires, direct from batteries to the plug, and we have had better luck.

Use a meter and check the voltage at the plug, that should tell you if getting 24v or 12v. A 24v will run on 12v but quite a bit weaker.

Also look at the wire wire it connects to the O ring connectors. If you see any corrosion "in" the strands, I would recommend clipping the O rings off, getting rid of corroded length of wire, and putting new "good" O ring connectors back on. That was an issue for us this spring.

Good luck.

[Savage Brewer]

I would bring a voltmeter on the water with you.

Measure the voltage with the motor off, 25%, 50% 75% and 100% thrust.

See what the voltage is at, you might find under higher current the voltage might be dropping off.

I need to do the same with mine when I get out with it.

[Ufatz]

You might also consider that the problem is in the motor, not the batteries.

[BobT]

You had the battery tested but did the electrolyte level get checked? Batteries that are low will lack capacity. Could check if you haven't already.

[CaptainMusky]

Check voltage at the receptical where your trolling motor plugs in. Check for a blown in-line fuse somewhere.

It is possible that the problem lies with your trolling motor, but its easier to rule out batteries first.

[Fishinguy40]

When was the last time you pulled the prop off your trolling motor and cleaned behind it? I do this a couple times a season. Every time I pull it off I find a wad of fishing line wrapped around the shaft. This adds resistance to the prop turning and could add to the drain on your batteries.

[harvey lee]

I had this issue once and I checked my cables and there was alor of corrosion inside the housing of the cables. I put new ones on all locations and then I was good to go.

As suggested above, I would pull the prop to make sure a bunch of line is not wrapped around behind the prop.

[Scoot]

Thanks much fellas. I checked at the plug and I've got 24 volts there. I checked the TM prop right away and all looks good there. I'll pull all the connections as soon as I can and replace all of them and see if that helps. After that, I'll call a local TM guy and ask if he thinks it might be the TM itself.

Thanks for the help!