Theory behind "exploding batteries" ?

Could someone please post the basic theory behind "rate of power draw" or whatever it is that supposedly makes batteries "disassemble" if they are overworked? I have been told something to the effect that if I put a high power bulb into a flashlight that was designed for alkaline batteries that I will "void the warranty in a rather dramatic fashion".
Any comments would be appreciated. Thanks
$tainless

batteries explode due to pressure buildup that does not vent.if you short an alkaline it will just get hot.the most likely danger from a high power bulb is a melted reflector from the heat.

Most, or all NiCd and NiMH have a blow valve that opens if it gets too hot. If you rapid charge it too fast, it opens, allowing the pressure to escape.

If you notice white dust or crust around the battery tips, your battery is open, and doesn't have long to live.

This is kinda off topic, but one time while a bunch of our friends were camping, one of our friends dumped our trash in the campfire. After 30 mins - 1 hour, we heard this loud POP, almost like a small handgun going off. It was enoegh to wake me up from my mid-day nap! I ran out my tent to see what happened and it turned out a AA battery that was in the trash can exploded.

Upon hearing it explode I heard something fall on the roof of our tent - like a seed or something falling from a tree. We found a peice of the battery on top of our tent and it turned out that the thing that flew out of the battery was the negative terminal of the battery, INCLUDING a VERY SHARP needle type structure that looked like it would make contact with the acids within the battery. Upon finding this i freeked out becuase usually batteries are thrown away in pairs or more. So we all freaked out and moved away from the fire while i looked through it with a stick. I was scared shitless becuase we had a deadly projectile that was ready to go off at any second and i was walking around the fire and poking through it while my crotch was directly above it! It turned out there was only one battery in the fire and there were no further instances.

Anyway...you asked about exploding batteries in your title...so i gues there is some relavency in this.

How about leaking, as opposed to exploding? What causes that? I recently saw that twice with alkalines. In each case, no damage to the product occured. A little of the contents had oozed out around the negative terminal.

The battteries were installed correctly in a product being used normally. In both cases, the batteries were nearing the end of their useful life.

Re: Theory behind \"exploding batteries\" ?

Please use this link to find out more:
http://www.cdc.gov/niosh/fact0002.html

link was given to me by Doug

anyway does lithum batteries produce hydrogen?

Re: Theory behind \"exploding batteries\" ?

Any battery develops hydrogen when over(dis)charged/overheated. Hydrogen plus oxygen (from air) are an explosive gas mixture. All you need is a small spark -- and BOOOM.

The pressure buildup snakebite and PhilAlex are speaking of is the developing hydrogen inside the battery. If the pressure from hydrogen is not relieved, the pressure will rupture the battery (which is not a chemical explosion). Then the hydrogen comes in contact with oxygen, and you may get the gas explosion (say, battery in fire).

If the pressure is relieved (through cracks or the blow-out valve of NiCd/NiMH/Lithium) the explosive gas form outside the batteries (inside the charger, if it happens due to overcharging). Removing the batteries from the charger may easily induce a spark, with your hand right at the explosion site.

Re: Theory behind \"exploding batteries\" ?

Never had one blow, just the leak. No problems with cr123s, yet. Mainly with alklines.

With deep cycle and lead acid batteries they have vents. Wet cells or flooded can boil off the water and need to be refilled. Gel cells have a limited moisture in them and when its gone it is gone or so most say. I did read somewhere you may be able to add water to a dry gel cell and get mroe life into it, but havent tried it myself.

Those lead acid ones vent too and in fact if you over do it, you need to wait for the gas to vent before thebattery can continue making power. THis is why when your car wont start you crank it and it slows and stops cranking. After a few minutes you go to crank again and you have some extra power or the battery seems to magically recharge itself.

Re: Theory behind \"exploding batteries\" ?

[ QUOTE ]
cobb said:
Never had one blow, just the leak. No problems with cr123s, yet. Mainly with alklines.

With deep cycle and lead acid batteries they have vents. Wet cells or flooded can boil off the water and need to be refilled. Gel cells have a limited moisture in them and when its gone it is gone or so most say. I did read somewhere you may be able to add water to a dry gel cell and get mroe life into it, but havent tried it myself.

Those lead acid ones vent too and in fact if you over do it, you need to wait for the gas to vent before thebattery can continue making power. THis is why when your car wont start you crank it and it slows and stops cranking. After a few minutes you go to crank again and you have some extra power or the battery seems to magically recharge itself.

[/ QUOTE ]

very intresting... after i read this a fren of mine has this problem... i asked him how old is his battery, he says its only bout couple of months... I asked him if he had this problem before changing battery, he says no..