[nu11eaf]

Water proof sports key fob Update:
After getting another "key fob battery low" message this morning I decided I had nothing to lose so I carefully ran a stanley knife blade round the fob until I managed to prise apart the cover to replace the battery.
The original battery was spot welded to its contacts on both sides so I had to prise the edge of the contacts up enough to get a grip with a pair of long nose pliers and wind and peel the contacts back like opening a tin of corned beef, this did the trick and the tiny spot welds parted (they were held on very well, enough to pull the back of the old battery up before parting).

I replaced the battery with a CR 2032 cell, I took the yellow plastic from the old battery and fitted it around the edge of the new battery, it prevents a possible short circuit from top positive contact to the negative side edge of the battery, I have just fitted the battery without soldering the contacts to the battery as the cover held them tightly in place.

After testing it worked ok I super glued the cover back on and ran some black tape around the edge to prevent any dust etc getting in, I gave the fob a good test by dropping and banging it around to make sure battery contacts stayed in place and jobs a goodun.
The fob is always in my trouser pocket and is never seen so not bothered about how it looks with the tape around it but it actually looks ok.