DIY....replacing battery in key fob....
 

1) Ok so here is my first "KEY DIY"attempt at a detailed also if you mess up your own key trying to do this don't yell at me!

So I have the 2 key fobs that came with my car when I bought it used. One I use everyday and the second one has had a dead battery since I got the car. When I called the dealership they wanted like $260.00 for a new one. I did a search around here and found you could get deals and what not and possibly get it down to around $90-120 bucks.. still way too much in my book since I already had a working key.

After talking to RICHIRICH who had taken apart a key fob . I decided what the hell the key was already dead anyways...

Here is the key before I tried anything..
http://farm4.static.flickr.com/3583/...0c2d5d50_o.jpg

2) I then proceeded to take a matt knife and xacto knife and basically carefully cut the key open along the seam where the top and bottom joined up.
http://farm4.static.flickr.com/3614/...78e6fd02_o.jpg
3) Next I took a small chisel and broke the spot welds on the battery that connected it to the rest of the circuit board.
http://farm4.static.flickr.com/3410/...053229a2_o.jpg


4) Once I had the battery out I looked at it and took the model number "a panasonic VL2020 3v" I found the exact same battery on ( VL Lithium Coin Cell Batteries 3V 20mAH 2 PIN VERT )Mouser Electronics - Electronic Component Distributor for $4.73. Once I got the battery is was a simple matter of soldering the new one in and making sure everything fit back together.
http://farm4.static.flickr.com/3361/...476b9e63_o.jpg

5) Before I glued it up I rubber banded the thing together and went out to my car to see if I could program it.

Put the working key in the ignition. Turn to position 2 for like 1 second then back and remove the key.

Press and hold the "unlock" button then press the "lock" button 3 times, you should hear all the locks cycle through.

Now take the non working key and press and hold the "unlock" button then press the "lock" button 3 times.

Then turn the ignition on and off again to end the programming....

I took the car for a drive to charge up the battery. Once I was certain it was all working I glued up the key again with some super glue....

Here is a pic of the key being glued.( I used liquid glue)
http://farm3.static.flickr.com/2434/...51ba2c2c_o.jpg


6) While definitely not a hard or complicated "DIY" project I did save myself about $200 and had fun while doing it...

Thanks again, MacGyver...I mean mrbmwx5. :D

Nice i did the same thing to the key that came with with my x5, but i just could not get over how used and ugly it looked, so i just replaced it with a new one :D

Excellent Job :thumbup: But be careful with soldering the battery for all those who wants to attempt this. If the battery gets too hot, it can explode on you...not a pretty site when you're only inches away from it. That's why the original battery was spot welded or tacked on.

Nice work. Can't beat the cost!


dkl: looks like the new battery has pins welded on already so any soldering would be on the circuit board not the battery.

i did the same mod and fucked up my key... i guess my key was just really dead. ig ot a new battery and put it in and resoldered it, nothing happen. Maybe because i only have one key, since you need 2 keys to complete the programming.

good job once again Tom... you should be in the Xoutpost's "Hall of Fame"... :thumbup::thumbup:

Agreed...but for an amature in soldering, if you leave the iron on the pin too long (the iron needs to touch the pin/circuit pad to solder properly), the heat from the iron can easily conduct to the battery in no time at all. Just be CAREFUL...that's all I'm saying.

Unfortunately I went the route of buying a new key when my key fob died. Paid $200 dollars for it. Hopefully when I do have some time on my hands, it wouldn't hurt to try to do this myself. Key is dead anyway, so it can't hurt. Thanks for the right up though... :thumbup:

Thank you! That will save my dying key!