Watch battery leakage -- usual causes, problem types, etc.

[xevious]

In the past I've had just one watch end up damaged by battery leakage... I'd left the battery in it for about 12 years, took it to a jeweler, and upon removal of the case back, a chemical mess was revealed. The movement was damaged beyond repair.

I've recovered a couple of watches since, one where the battery had been in it for about 14 years. The battery had some chemical crystals on the surface, but thankfully no presence of chemicals in liquid form. So the watch movement was saved from destruction.

I'm curious to know what typically causes watch batteries to leak. Do they all have the same potential to leak, or are just certain battery types more prone? I'm suspecting that the thinner the battery, the less chance for leakage due to less battery material... so, the big old button cell batteries might tend to be "watch time bombs". Will colder temperatures help prevent leakage and does very warm temperatures encourage leakage?

[azimuth_pl]

hey,
not sure about the temperature influence but the old batteries were not that perfect to start with and they were not alkaline or silver oxide like nowadays.
these tend to powderize whereas the old 70/80s types usually leak acid severely. however "powdered" modules also might appear to be damaged without any visible traces.

[retroleds]

I'm curious to know what typically causes watch batteries to leak. Do they all have the same potential to leak, or are just certain battery types more prone? I'm suspecting that the thinner the battery, the less chance for leakage due to less battery material... so, the big old button cell batteries might tend to be "watch time bombs". Will colder temperatures help prevent leakage and does very warm temperatures encourage leakage?

Unless defective, most batteries won't leak until they are dead - at that point their chemistry is generally reversed(alkalines become acid, acid types become alkaline). Popular Science had a great article on batteries about a12-18 months ago...I placed a link somewhere but can't find it.... Cold storage of batteries is tricky - their amprege potential drops greatly, so I would recommend you never test a watch you just pulled out of the mailbox until it has thoroughly warmed up. Otherwise, you may drain it substantially thru just a few displays...and the warming is not going to recover the same percentage of potential that the cold usage just took away. Real hot temps(left on car dashboard,etc. can cause some to 'puke'.

Regardless[virtually] of the outside temperature, the inside of your watch will be between 75-86 degrees faren.(due to your body giving off or absorbing heat, as the situation demands) - according to the American Watchmakers Institute. I'm thinking a plastic back might throw that off a bit.

[xevious]

That Popular Science article sounds intriguing. I'll have to look around for it!


As for leakage, I should've said I was considering it for dead batteries... I wonder if all of them end up leaking to some degree if left inside the watch for a long time, or are there circumstances that prevent it (high quality battery casing, circuitry that stops trying to draw power below a certain voltage, good watch case temperature insulation, cool and dry storage environment, etc.).