Hot Battery

I had a AA battery in my hangbag and noticed that it became very hot to the touch. It wasn’t connected to anything (it was floating around in my bag as an emergency walkman battery replacement).

I’m wondering if anyone knows why it became hot and what I should have done to dispose of it.

I looked at a couple battery related websites, but couldn’t find anything to explain this phenomenon.

Do you have anything metal in your handbag? Perhaps a foil gum or mint wrapper? If so, it’s possible the terminals were shorted by it.

I read of a case years ago where a guy dropped a 9v battery into the pocket of his down jacket. A few minutes later there was a pop and a puff of feathers. Seemed he had a .22 round in his pocket that shorted the terminals.

When I was in the military, during winter field exercises fellas would hook nine-volt batteries together and stick them in various pockets. I was always leery of leaks, but they claimed no problems.

Do not try this at home. Professional driver on closed track. All the usual disclaimers apply.

Upon inspection, I did have a foil wrapper in my bag, along with coins and another AA battery (no bullets). Strange that only one battery got hot.

Did/would the battery cool down after it was out of the volting environment? Where should I have put it?

It’s not so strange that only one battery would get hot. It’s a lot harder to short the terminals of an AA battery than it is to short the terminals of a 9v. The one that got hot was probably “just right” in the foil and/or coins so that it shorted and maintained contact. The other one either didn’t short at all; or if it did, the terminals did not maintain contact with the metal.

I think you’ll find the battery has cooled down by now, but it took energy to generate the heat. It’s at least partially discharged.

There’s nothing wrong with putting a battery in a handbag. Just make sure there is no metal for it to come into contact with. I suppose if you want to be sure it’s isolated you can put it into an appropriately-sized plastic pill bottle. Or you can keep a couple of batteries in a plastic cigar tube. Or put electrician’s tape over the terminals.

Thank you for the advice, Johnny! I will opt for the cigar case so I have an excuse to smoke one.

not all that hard, in some AA batts all you have to do is short the tip (or bottom) to the side - which can easilly be done with a single coin or key. The side of the batt is one pole (usally - ) and the material on the side expecially near the tip or tail can get dammaged and allow the metal to be exposed.

I take a great many photos in my role as a newspaper editor and I used to carry spare AAA and AA batteries in my pants’ pockets for my cameras. A few times I would find my leg burning as if I had a hot foot in the wrong part of the limb. It was as you explained, a hot battery that had come in contact with some change.

I finally ended up cutting the fingers off old ski gloves and stuffing them in there. It kept the batteries easy to get to and gave me some interesting bulges in my trousers.

k2dave: I hadn’t considered a damaged battery.

TV time: Interesting trick.

If you really want a hot pocket, drop a 9v battery into a pocket that has some steel wool in it. The steel wool will catch on fire! :eek: (No, I haven’t done this accidentally; but I have ignited steel wool with a 9v battery to prove to myself it works.)