Why do Alkaline Batteries Leak?

[David Carlson]

Occasionally, we get back Symphonie loggers that have been damaged by leaking batteries.  Usually, these are critically damaged due to the caustic nature of potassium hydroxide, the chemical that is exuded.

Alkaline batteries, like the D cells that the Symphonie/SymphonePLUS loggers use, are sealed, and should not leak.  However, several factors can contribute to the breakdown of these seals.  I have included some information below.

While there is no failsafe way to avoid it, there are ways to prevent battery leakage from occurring:

• Don't mix batteries: Installing batteries that are different in contruction or charge can lead to reverse charging, which can lead to leaks.

  • use two of the same brand

  • from the same box

  • install at the same time

• Install new batteries

• Do not install dented or damaged batteries - batteries that have been dropped are more likely to leak

• Change batteries every 6 months to 1 year

The following is an excerpt from the Candle Power Forum (http://www.candlepowerforums.com/vb/showthread.php?t=171520):

DONT MIX
beyond them being discharged, there is the reverse charge issue, which gets many consumers, because they just stuff some battery that fits into a device.
EVEN though the instructions on most of these devices, in the first part of the manual with all the rest of the garbage nobody reads :-) it says, dont mix brands, styles, types, age, or drain ammount . well something like that.

when you use batteries in SERIES, you should use the same brand, the same type, the same package, the same ammount of use, if you mix up batteries in a drawer (we all do even me) then toss them in something, one could be WAY different capacity.
so ONE cell dies and the others keep going, and the one that died gets a reverse charge, and that can make it more Likly to leak.

AGE
a second factor is AGE, even if the cell is unused, there is toxic corrosive materials being contained to give you power. the Can that holds this stuff eventually breaks down over time. the more the manufactures shrink the can, to get more capacity, the sooner it can break down. then of course there is probably plastic linings and stuff, but all are effected by age. some manufatures push the edge of this containment envelope to far.
and over time , even without using the battery an old cell might be way low in capacity, which puts it back in factor 1 , one cell dies early.

TEMPERATURE
batteries can see temperatures ranging from 140*F  to -20*F throughout the course of a year, and temperatures can cause expansion and contraction of anything, loosening things up , or expanding them to failure.

RUST
most all of this stuff is indicated on some packaging or spec sheet somewhere, but even if you do everything exactally right, stuff still fails, it just fails lots less.

CHECK MORE
check the cells say once every 6mo or so, it takes time to do the major damage, and the cells show inconsistancies before they ruin everything. look for changes in color on the wraper, Rust forming on the metal, or what looks like a liquid oil changing the coloration of the wraper.

DAMAGE
denting a battery , even from a hard drop on the floor, even a rechargable, even if you dont see the damage, an internal short can occur, which can discharge the battery or reduce the effectiveness of the seal.