Trolling Motor/Battery Help

Marley · Post by **Marley** » Sun Feb 10, 2013 7:45 pm

I have a motorguide 24v 82lb tour edition trolling motor on my 18'6" bass boat. Normally I can make it a full day on fully charged batteries, the last 3or4 trips I can barley make it 6 hours with very similar use habits (speed, current, vegetation, etc).

After last trip I charged the batteries as normal, on board charger, took both batteries out of the boat, one read 12.52 v and the other 12.76 v. I then took both batteries to the local auto store and both passed a load test.

Is there anything else that could be draining the batteries faster than normal? (No other accessories are connected to these batteries)

A Perez · Post by **A Perez** » Sun Feb 10, 2013 8:11 pm

Before giveing up on them put them on a slow Trickle charge some times that's what they need. Good luck.

george · Post by **george** » Sun Feb 10, 2013 8:14 pm

Do you have them hooked up properly?
With a 24V set up the two batteries should be hooked up with red coming from Trolling motor going to positive (+) on battery 1 and black coming from Trolling motor going to negitive (-) on battery 2 as well as the two batteries being connected by Positive (+) on battery 1 being hooked to (-) on battery 2. This will complete the 24V circuit! I have seen folks hook them up incorrectly and it will run your batteries down quicker draining one then the other.
Call Gene at the Hook line & Sinker, he is an expert on this stuff and can probably give you a solution over the phone.

George

scottsweet · Post by **scottsweet** » Sun Feb 10, 2013 8:16 pm

Marley,

How old are your batteries?

The load test the auto parts store did isn't going to tell you much from a duration/capacity perspective. Basically the test will tell you that they are holding a charge and there isn't anything physically wrong with them.

They are a little out of balance, but not too bad. The one that is 12.52 is weak which is going to cause the other battery to work harder.

rico · Post by **rico** » Mon Feb 11, 2013 12:14 pm

The best way to check your batteries is to fully charge them and let them sit for an hour before you take the readings. A fully charged battery should read 13.2 A reading of 12.5 means your battery is half gone. That's why your batteries aren't lasting. Time to look for new batteries

scottsweet · Post by **scottsweet** » Tue Feb 12, 2013 5:20 pm

rico wrote:The best way to check your batteries is to fully charge them and let them sit for an hour before you take the readings. A fully charged battery should read 13.2 A reading of 12.5 means your battery is half gone. That's why your batteries aren't lasting. Time to look for new batteries

Rico, I think that some of this information is not completely correct. The best way to check a battery is what you said, but let it sit overnight to completely cool. The resting voltage of a good lead cell battery should be about 12.7-12.75 after they have completely cooled. AGM batteries are different and may have a higher resting voltage.

A 12.5 voltage after a full charge and then a complete cooling is not that bad, but shows a weak battery as I said. Without knowing how they were charged and how old they are, it is hard to tell.