1988 535i/E34 - Battery for the Key Light

I know this is rather a trivial item but I've got everything else working perfectly! Does anyone know what the correct battery is for the key for a 1988 535i/E34 which powers the little light? I've tried a few of those shopping centre bars that sell batteries for watches and none of them have anything that fits. The little bulb is rated 1.5 v and 0.09 watts. I haven't tried the BMW dealer yet. Thanks in advance.

I suppose I should have tried searching for this before but I have just discovered a seller on eBay who is offering a complete replacement for the key insert including the light/ button/battery assembly for $24.95 (item #160036266893) which I have now ordered. It even has the BMW roundel light button in colour. Cheers, Steve

There is a writeup about changing to leds. It isnt really helpfull with battery type. Seems like they just change to cellphone battery packs.

http://evansweb.info/articles/2003/0...d-modification

Were there any numbers on the battery?

I saw that item about changing the keylight over to an LED. I didn't have the old battery for the key light but the new replacement BMW roundel battery/button/light unit has now arrived from the U.S. and it had a Varta V 625 1.5 v battery in it. I gather that this is a mercury battery type that is no longer considered safe to manufacture for environmental reasons and may now be difficult to replace. Anyway, my key light works fine now and the replacement unit had a nice coloured metallic BMW roundel as the button press which looks much better than the colourless black plastic one that it replaced. Cheers, Steve

I am interested in finding out how to open the light up compartment on a 1988 735i BMW key??? Any ideas will be helpful!!!

I went to radioshack for my replacement. They carry the right size. I regret doing it because It's not that bright, and the insides constantly need to be cleaned for it to work.

Josh429er, may I suggest any of the contact cleaner/contact lubricants RS sells? They used to sell two, one ok, the other nice and they knew it. Otherwise, Caig Gold has a good rep, as far as I know. You can get it at Parts Express (you reading this, guys?) and other places. hope its useful, Craig

Originally Posted by wrldsgretestBMW

I am interested in finding out how to open the light up compartment on a 1988 735i BMW key??? Any ideas will be helpful!!!

if i recall correctly, push the bmw roundel down and then slide the back to the side and the whole assembly will come free of the key itself. I dont have a key of that type on my current BMWs to confirm though sory.

It's quite easy, just requires some soldering and the right battery.

i came across the battery for the key at bavauto a while back, apparently the battery changed for cars (or keys) with a 1/1995 or later build date.