E46Fanatics - View Single Post - Diamond Key Battery Replacement
View Single Post
Old 06-18-2007, 10:30 AM   #1
Registered User
Join Date: Jul 2006
Location: Seattle
Posts: 8
My Ride: 2001 325 CI
Diamond Key Battery Replacement

Okay, my wife had to buy a new key for her 2001 E46 for $225.00 because the remote in the original key would not charge up no matter what. After searching for all of the forums, I have found there is no real concrete answer about replacing the battery in a remote. Since I had an old one, I figured "what the hell" and I would give it a go. Here is what I found out...
You CAN replace a battery, but you must have a little patience and some special tools.
Here is what you need:
1) Small jewelers screwdriver (flathead)
2) Razor blade
3) Soldering gun
4) JB weld ($5.00)
5) New battery (Panasonic VL-2020 Lithium Coin Cell battery: $5.00)
6) Super glue ($2.00)

I could not find any place in Seattle to buy that battery, so I found a place online called Mouser Electronics (www.mouser.com), and got one for $5.00 and $5.00 shipping, so ten bucks for the battery.

Replacement Procedures:

1) Gently pry open the key by forcing the screwdriver in the rear center of the key. You will score the plastic, but the battery sits back there and you are away from the electronics for the remote. My key split open fairly easily, but the edges were rough, so I smoothed them down with the razor blade.
2) Pop out the board inside of the key, you can't miss the battery. You can see the battery has a positive and negative lead soldered to the board. Using your soldering gun, melt off the solder that is holding the leads to the board. The battery will fall off.
3) The leads on the battery I got were similar, but did not line up exactly, so I had to bend one of the leads to fit the hole pattern on the board. You can also pry off the leads on the old battery if you want, they are tacked on, but you can pop them off with the screwdriver. My soldering skills are lacking, so I used a little dab of JB weld to hold the new leads in place.
4) Put the board with the new key back into the key housing. Put a little super glue on the edges of the housing and press the two parts of the housing together until they are secured (Make sure the board and battery are installed correctly!)
5) You have to initialize the key. (This is covered a lot in the forums.) You must do both keys at the same time. I re-initialized the new key, then the old one I had just put the battery in. Both checked out, viola! Extra key now works!

So, 15 minutes later and about $20.00, I have an extra key that is fully functional. If you want to save $200 bucks and have a little time, you can make an old key remote work again, or just use your key manually. Hope this helps someone!
benmuellerb is offline   Reply With Quote
Ads by Google

Guests, get your FREE E46Fanatics.com membership to remove this ad.