Minn kota 24 volt question

[slabeye]

Ok, I have 2 different sets of batteries and 2 different plugs on the boat. 1 set does good and the other set runs for about 3 hours and it is like the batteries are dead. I have checked both batteries twice both times they are at 12.6 volts and says they have 77% and 83% life in them. Checked connection and they are ok. Changed the plug on the boat. Wires are not getting hot. One battery is a size smaller than the other. So my question is can the wiring just be bad if it runs for 3 hours ok and then hardly any power.

[CrappiePappy]

Rodney ... I hear people saying that both batteries should be equal size, and bought at same time (with a mfg date as new as possible and as close as possible to each other) ... otherwise the weaker/older battery will draw the other one down to its level.

Secondly ... have you had the batteries load tested ?? All the plugs/connections may be good, but one battery may have a weak cell that's draining on the other one.

[wicklundrh]

I would say you have a bad battery.

Charge them both up and take a reading. IF the battery shows 12.6 volts at charge, it isn't any good. I had the same issue last fall. Both batteries charged and I would get about 3 to 4 hours before being dead in the water (typically get 8 to 10 hours). Did a battery test after charging. One showed 12.6, the other showed 13.4 (or something like that).

Catfan is the guy to talk to in my opinion. That guy knows his batteries and his information and knowledge has helped me better understand things.

[slabeye]

Every bad battery I have came across has a big difference in volts after using it. I wouldn't think if 1 was good and 1 bad there would be a difference in volts right after a charge and then 3 hours later they would be the same. But I will check it before I go next time. Thanks

[slabeye]

Shouldn't a battery with a bad or weak cell. Have less volts after using it as the good one. The tester I use shows volts and the life of the battery. After yesterday they both showed 83% life left in both batteries....all the rest of bad batteries I have had one battery would say 75% and the bad one would show something like 25% left.

[strmwalker]

Shouldn't a battery with a bad or weak cell. Have less volts after using it as the good one. The tester I use shows volts and the life of the battery. After yesterday they both showed 83% life left in both batteries....all the rest of bad batteries I have had one battery would say 75% and the bad one would show something like 25% left.

what kind of tester are you using ???

[slabeye]

It is a handheld battery charger. Same way I have checked batteries for years.

[strmwalker]

It is a handheld battery charger. Same way I have checked batteries for years.

just curious !!! If it was me I would get the batteries in question load tested !!!

[Cray]

You have a bad battery, charge let sit a couple of hours and check voltage. Like others said one is bad and dragging the other one down. Just went through this 2 weeks ago. Best to get a inexpensive multimeter and use it to check voltage.

[Osnola]

Mine did the same thing...problem was not fixed until I bought 2 new batteries...tried it by replacing only the bad one but about 2 hours on the water and TM was dead...Get two new batteries, some size, same kind and you will be good to go...