Hot Positive Battery Post on Cranking Battery

Kentuck · Post by **Kentuck** » Wed Dec 08, 2010 7:32 am

I've had a development on my cranking battery. It happened once earlier this summer that after trying to crank the big motor, I loose all power, even to my electronics. Checking the connections, I found the nut on the postive post connections loose and when I went to tighten it, the nut was really hot.

Then last week I was going to take the boat out and since I hadn't had it out in two months, I went out the night before and hooked the water up to it to get started and let it run a minute. Of course it took some cranking to get it fired up. I then went to hook up the charger to make sure the batteries were good. I opened the battery compartment lid and there was smoke. The wires connected to the postive post on the cranking battery were fried. Lucky they didn't actually catch fire. Anyway, anybody have an idea about what might be going on? I've looked for a bare spot on the big motor cables to see if there is a short there but I don't see any. I have to replace the wire connectors now.

Bill K · Post by **Bill K** » Wed Dec 08, 2010 8:12 am

Sounds like you have a grounding out cable/wire somewhere. Putting new cables on may stop the problem and you will probably find where it is grounding out when you find the bare spot/burn area contact. Bill K

DAKINE198 · Post by **DAKINE198** » Wed Dec 08, 2010 10:33 am

Leon Pugh · Post by **Leon Pugh** » Wed Dec 08, 2010 10:53 am

Are the connectors burnt or the wires as well, It sounds more like a poor connection at the battery which can create enough heat to melt the connectors and the wires close to the bad connection.

Give me a call at 916 813 0321 and I can walk you thru repairing it.

Kentuck · Post by **Kentuck** » Wed Dec 08, 2010 2:51 pm

Just the connector ends were melted. Rest of the wires are ok. Leon, I will try and call tomorrow afternoon if that is ok.

propgun · Post by **propgun** » Wed Dec 08, 2010 9:07 pm

Had the same problem I had drained the battery so low that it reversed it self. had to buy new battery. .

Kentuck · Post by **Kentuck** » Thu Dec 09, 2010 8:36 am

Interesting. I may go the new battery route. I know it is at least 5 years old as that is how long I've had the boat. A guy at the parts store told me that sometimes a cell inside can come loose and lay over onto another cell and that could cause heat to transmit to the terminals.

Oldschool · Post by **Oldschool** » Thu Dec 09, 2010 12:25 pm

The basics; test the battery with a load tester. Change the wing nuts to stainless steel hex lock nuts and use flat washers. Clean all the connections on a regular schedule and cover with vasoline after tightening the connections. Make sure the batteries fit the tray and are strapped down.
You should have a switchable On/Off 50 amp circut breaker on the cranking battery and switched off when charging.
If one battery is bad after 5 years, change out all of your batteries as a set.
Your over heating is more than likey do to a loose or corroded connection at the battery post.
Take Leon up on his offer to help you!
Tom