These watches don't use a battery per se, it is actually a capacitor. I don't usually work on non-mechanical watches, but I was asked to take a look at one of these before with the same problem. I replaced the $25 capacitor, and it did not 'fix' the problem.
I gave up at that point, since they are otherwise just a circuit board which I know nothing about. Perhaps the charging circuit fail in these?
Thanks for the reply, Philip. The instructions that came with the watch say that this model does have a rechargable battery, #CTL1616. I can replace this watch for under $50.00, but I really expected longer than 2 years out of this battery. The internal light stopped working after one year, so maybe the quality just isn't there in this one. I am hard on watches, so spending money on an expensive watch would be a waste. This one says it is module # 2531, if that helps identify it.
Philip, what does this capacitor look like? Is it similar to a button battery?
Since this didn't cure the problem on the one you worked on, I will likely pass on it. If I put my watch under a 60 watt light bulb for an hour or so, it is good for a couple of days. I think Santa may have a new watch for me
Well, I replaced that battery/capacitor a couple of weeks ago, and it seems to be working fine now. Total cost, $5.00. Hardest part of the job was getting the watchband off to get to the screws on the back (I'm not a watch guy).