On 8/1/2012 3:19 PM, Steve B wrote:
I have two Garmin 12XLs. They are so old that the little lithium memory
battery has gone dead. I did manage to get the cover apart. The tiny
little battery was flash soldered in there, and on the third soldering iron,
was able to get the old battery off. Hope I didn't screw up the board with
the heat. Now to install the new battery. The holder is like your finger
and thumb pressing together, and there isn't much there. For now, I am
trying to SuperGlue the tabs to the battery, and when that is dry, hit it
with the goodest soldering iron, and hope I can do it fast enough not to
damage the battery.

I do not think that the clips will hold the battery while banging around,
hence the SuperGlue to hold it in place, then a second means of fastening it
in there. My other idea is to find some electrically conductive SuperGlue
or epoxy type stuff that will bridge any gap so as to make a connection,
plus to hold it in there during the bumps of the boat ride.

Does anyone have any experience with such goo? This is a very tiny
soldering job, and I can do it, but I just fear the heat will kill the
battery. Perhaps I can even make a tiny piece of shim stock, put it between
the tab and battery, then SuperGlue the shim stock in place.

Anyone done gnat castration on small circuit boards like this? The first
one is still drying the SuperGlue, and I'm not sure it will even recover
from the treatment. The second one is waiting, and now I know how to get
the battery out faster, and it should have a higher chance of surviving
surgery.

Steve


I'd measure the current drain. If it's only keeping some ram alive
and the current is in the few uA region, conductive epoxy should work fine.

I'd not try to solder the battery. People will tell you that you can do it.
And you might be able to with some experience. First time, probably
not. Eye protection is a MUST.
I use a battery tab welder. Even that heat depresses the voltage somewhat.
You can buy batteries with tabs attached. That's the best way
for most of us mortals.

In a pinch, you can fold over some wire to make a lump and use
heat shrink to hold it in contact.