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

"Steve B" wrote in message
...
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

What I have usually seen is that the tabs are first spot-welded to the
battery (with two tiny electrodes on the same side of the battery to avoid
sending current through it) and then the tabs and battery are installed in
the board. This may explain why you had such trouble getting it apart,but
the welds are small enough that tugging on them will break them.

However, I have also seen people succesfully solder to a coin battery. First
remove the battery and thoroughly clean off the super glue you applied, it
will only get in the way of wetting the surface. Wet the tabs with solder as
well as the two sides of the battery before assembling. Applying a little
non-corrosive flux first helps. Then instal the battery and re-melt the
solder.

Alternatively, if you can find the same style battery with similar tabs
attached, you would de-solder the tabs from the board and replace the
battery. Here is an example:
http://www.digikey.com/product-detai...P294-ND/447503

"Steve B" wrote in message
...
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


Perhaps:

Buy a battery with tabs, if it doesn't fit the pcb, run small insulated
wires from the battery to the old tabs or the PCB.

Protect against shorting with heatshrink & then use double sided tape or hot
glue or neutral cure RTV to locate the new battery.

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.

"Dennis" wrote in message
. au...

Buy a battery with tabs, if it doesn't fit the pcb, run small
insulated wires from the battery to the old tabs or the PCB.

Protect against shorting with heatshrink & then use double sided
tape or hot glue or neutral cure RTV to locate the new battery.

The clerk at the Interstate Battery store spot-welded some tabs on for
me.

jsw

On Aug 1, 4:19*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

Those tabs are spotwelded to the battery. The reason they aren't
soldered is that you'd have to boil off the water on the other side in
order to get the case hot enough to tin. Same reason you drain copper
water lines before soldering. So even if you DID manage to get a
solder joint, the cell would be damaged. Tabbed lithiums are readily
available, just not off the peg at mongo mart.

Conductive epoxy is only nominally conductive, but might work with the
low power drain requirements of a backup battery. You could buy a
raft of tabbed cells for what a set of tubes of conductive epoxy
costs, also not on the peg at mongo mart. Check the likes of Digi-Key
and Mouser.

Stan

Well, I got one of the batteries to cut loose, and got it out. I then took
the new one, and an alligator clip. I put little tabs of plastic so the
alligator clip would not make a circuit, then clamped the battery between
the two tabs, and SuperGlued it. It is working so far this morning. This
is the memory battery that stores all your waypoints when you pull the main
batteries. If that dies, I will take it out, and either go and buy a
battery holder, or make one, and run two small wires to the exposed metal
tabs that used to hold the battery. After heating them, there is no spring
left in them. And if that don't work, I will just go get a new GPS.

I was able to find a historical record on Google Earth of a local lake as it
was filled up, and all the underwater towers, dropoffs, holes, and trenches
show up great. Then I got all the gps coordinates, changed to symbols and
made a map, which I then laminated. This gps'ing should put me right on top
of a tower, or over a hole or cliff, and improve my fishing. There are
largemouth bass, crappie, and huge bluegills in this lake.

I have been redoing my boat over the last three months, upholstery, and all,
and it sure runs and fishes good. New lights should arrive today or
tomorrow. The depth finder helps locate stuff, and between that and the
gps, the fish won't stand a chance.

Steve

On 8/2/2012 12:36 PM, Steve B wrote:
Well, I got one of the batteries to cut loose, and got it out. I then took
the new one, and an alligator clip. I put little tabs of plastic so the
alligator clip would not make a circuit, then clamped the battery between
the two tabs, and SuperGlued it. It is working so far this morning. This
is the memory battery that stores all your waypoints when you pull the main
batteries. If that dies, I will take it out, and either go and buy a
battery holder, or make one, and run two small wires to the exposed metal
tabs that used to hold the battery. After heating them, there is no spring
left in them. And if that don't work, I will just go get a new GPS.

I was able to find a historical record on Google Earth of a local lake as it
was filled up, and all the underwater towers, dropoffs, holes, and trenches
show up great. Then I got all the gps coordinates, changed to symbols and
made a map, which I then laminated. This gps'ing should put me right on top
of a tower, or over a hole or cliff, and improve my fishing. There are
largemouth bass, crappie, and huge bluegills in this lake.

I have been redoing my boat over the last three months, upholstery, and all,
and it sure runs and fishes good. New lights should arrive today or
tomorrow. The depth finder helps locate stuff, and between that and the
gps, the fish won't stand a chance.

Steve



I sure like to eat Bluegill! Probably the best tasting freshwater fish
on Earth.