melted battery post

[RDW]

This is really a land based question but it is about golf cart batteries hooked up in series, (positive to negative, 6 volt batteries, total of 6 batteries). I was driving my grandchildren around the farm and I heard a small pop and the golf cart stopped. I looked at the batteries and one of the battery post had melted enough to look down into the battery and the bolt that had connected to the battery post was totally loose since the battery post had melted off of the bolt.
What did I do wrong?
RDW

[GordMay]

Don't what, if anything you did wrong, but the battery has probably been somewhat compromised.

[cabo_sailor]

My first guess is a poorly connected cable that arced to the post, but hey, what do I know?

Rich

[saben]

You got it. Apply dielectric grease and make sure it's tight. If not it's a big fire hazard!

[Captain Bill]

My guess is a loose connection. Second option is a corroded connection. I once had a battery terminal bolted onto a copper wire that got a little loose and it melted the end of the copper wire. If it can melt copper it sure would not have any trouble melting lead. The problem is a result of pulling a lot of amps through a connection that has a higher resistance than normal but not so high that it can't conduct at all. The two most common causes are tightness of fit and corrosion. No other causes come to mind at the moment. Either way the battery is toast. Make sure the connection is nice and tight on the new one and as previously suggested use dielectric grease to prevent corrosion.

[RDW]

Thanks to all. I will follow your advice. Anybody want a well ventillated battery?
rdw

[btrayfors]

It's very easy to underestimate what "tight" means. That's why wing nuts are a no-no on a boat....you can't get them tight enough.

NB: there are lots of two-legged wing nuts on boats, and some of them are pretty tight :-)

It's good practice on land, too, to use proper nuts and make sure all connections are clean and really tight.

The dielectric grease is a good idea, too, even though it's non-conductive ("dielectric" means non-electrical conductive). It's to prevent the intrusion of moisture and contaminants, but the connectors themselves need to make good clean contact metal-to-metal.

Bill