Why do batteries leak?

[golok]

I have had the unfortunate experience of finding flashlights and other gadgets ruined by leaking batteries. Sometimes, I forget I have some devices in the drawer for a long time.

When I realise I have to use a flashlight or something that requires batteries, it happens that one or two of the batteries would have leaked, thereby ruining the flashlight.

Why do these batteries leak? By right, the battery should be properly sealed and only rendered useless when its power is either drained completed or is used up by an appliance.

 

[mwerner]

The chemicals used in most batteries are somewhat caustic, either acid or alkaline. I'm sure there's a trade-off between cheap manufacturing and leak-proof-ness. (hehe-did I just invent a word?)

 

[Warthog]

Try lithiums with the 10 year shelf life.

 

[Silver Puss]

Were these batteries of recent manufacture? I have not had that happen in a long time.

When I lived in the tropics, zinc-carbon cells would leak if left in the flashlight for only a few months.

A few years ago the alkaline D cells in my Sony ICF-2010 (which needs them even if you use AC) leaked powdery material all over the battery compartment. I believe the batteries were over 5 years old. As with corrosive ammo, I used hot water to clean up the mess. About an hour with boiling water and cotton swabs and the radio cleaned up nicely. There was surprisingly no damage.

 

[Quiet Storm]

Originally posted by Silver Puss
Were these batteries of recent manufacture? I have not had that happen in a long time.

Yeah, I too thought that leaking batteries were a thing of the past. They probably improved the alloy which the outer layer is made of.

 

[samo]

Dude ~ Its time to get yourself a surefire! Lithium cells don't leak..

Sam

 

[MelancholyMutt]

ANything you ever wanted to know about batteries, how they work, what they're made of, how to take care of them... why they work...

Handbook of Batteries... costs about 125 bucks at Amazon, but the most comprehensive book out there... I had the chance to skim over it but could not afford it...

 

[Keith]

Another reason they leak is that when they generate electricity they also generate heat, the heat causes the electrolyte to expand and force its way through any weak spots. I had one battery actually develop a visible bulge once when it had been stored in a hot car and used while still hot. Personally I usually don't have any problem with batteries in high quality electronics or flashlights leaking but do with cheaper stuff.