View Full Version : Deep Cycle battery and trolling motor question

11-10-2005, 08:19 PM
Can anyone tell me if accidentally ::) hooking up your trolling motor backwards (positive to negative, negative to positive) will cause damage to a battery or trolling motor?

Accidentally did this yesterday and now something is up with my motor or battery. I charged the battery today for about 2-3 hrs and tested out the trolling motor again. The motor seemed to go strong for a few minutes and then it slowed down (could hear the RPMs drop). Another odd thing is when I hooked the charger back up after this the check connection light came on the charger. I waited about 5 minutes and tried it again and it started working. ???

BTW: The battery (interstate DEEP CYCLE), motor (MK Endura 46lb) and charger (MK) are about 2 months old.

Thanks for your help!

11-10-2005, 10:23 PM
Reversing the polarity to the trolling motor would not cause damage to the battery. But it could damage the trolling motor if it had some electronic controls inside it. I can't explain what you saw when you hooked up the battery to the charger since I don't know what was happening through your description. My hunch is that the battery was hot when you plugged it onto the charger. A hot battery would display a higher voltage and the charger thinks its fully charged. I hope that helps you. If you want to talk about it pm me.

11-11-2005, 09:03 AM
I'm not sure what's going on. The charger still shows that it is charging, after 14 hours. I'm gonna have the battery tested where I bought it. My friend is the manager so he'll probably just give me a new one to see if that's the problem.

11-11-2005, 10:03 AM
If your trolling motor shorted out (The electronics failed with the reversed polarity) you may have damaged the battery (overheatting it with the short circuit). But you said the motor was running. Did you try hooking it to your car battery for a test?

11-11-2005, 11:09 AM
I doubt that you hurt your battery. It's possible the electronics in the motor got hurt. By the way, are you testing your motor in water or in air. Revving up the motor in air can cause it to spin too fast and is bad for the motor. A good idea might be to call Sunny's Electric Marine in Sacramento. He should be able to tell you what's going on with your motor. Good Luck.. Larry

11-17-2005, 06:21 PM
Thanks for the info. Took the battery to the place I bought it and it looks like it may have been a loose adapter.

I tested the motor (in water) after I got the battery back and it seemed to be fine. Guess I'll find out when I get on the water again!