This would make since..although.. they told me (at the dealership) it was a rechargeable battery when I bought the car and I dutifully stick it in the dash every few months just to charge it......

Done.. I'll just buy a battery or two and be done with it... Thx... Problem solved.

 

If it is a cabrio, it us a gen1 with a rechargeble battery...all keys in gen1 of that style is, and all refresh, meaning 2005+ model year cars till then end of gen1 had that key.
Range was never more than a few feet...mostly line of sight...maybe a few cars over...
And the older threads are not searchable by anything but Google...but the info is dated, links mostly dead...members gone..

 

One bit of info....
If you have comfort access on a gen2, it IS NOT RECHARGEABLE.... std key is, comfort access key is not...

 

Self-appointed first generation key expert here. This is a situation where a picture (or, in this case, drawing) can be a big help as the first generation/refresh/2007 but R52's until 2008 lines can get a bit blurry.



If you have a two button key that looks like #1 above and is somewhat "clamshell" shaped, you have a replaceable CR2032 battery inside. Look at it from the top and you can see how to pry it apart with a standard size screwdriver. I've replaced many on the keys I have repaired and while they test good with no load, once a button is pressed they will drop to as low as 2.6 volts from approximately 3 volts when new. A new battery will have an almost unmeasurable voltage drop when a button is pushed.

Key #2 above is the companion key to #1; it opens the door lock and starts the car but has no remote functions. You can pry it apart as well; a $20 folded up real small will fit inside making sure you always have some gas money. I suppose you could put other things inside it as well....

Both Key #1 and Key #2 also have a passive EWS/immobilizer chip inside which is read by the ring antenna around your ignition switch. This is independent of any remote functions your key may or may not have and allows the car to actually start after you turn the key.

Key #6 above is much flatter, has three buttons and a rechargeable battery inside that is charged by an induction circuit around the ignition switch. It is sonically welded together and is easy to destroy if you try to take it apart. These two places may be able to help you, as this style of key is also used on BMW's:
http://www.bmwgm5.com/Key_Repair.htm
http://bmwkey.com/
The first link has a great hall of shame with pictures of customer-opened keys. I have confirmed with them that they will repair three-button MINI keys.

Key #7 above is the companion key to #6 above but with no remote functions. You can't open it up to stash your weed or a $20.

Both Key #6 and Key #7 also have the EWS/immobilizer chip inside, independent of the remote functions.

Key #3 above is a plastic wallet style key that will open the doors in an emergency but is not designed for repeated use. It does not have an EWS/immobilizer chip.

Hope this clears up some confusion.

Val

 

thank you for this. I've been going crazy over this the last couple of weeks. My car keeps telling me my remote is dying (key + battery symbol) anytime I exit the car and lock with the door handle button (comfort access). I've been googling how to get the battery changed without going to the dealer.
Last night, I decide to look a little closer, and the the fob back pops off with just my fingernail. Looks like a pretty standard battery to me.
Now I know it is.

 

How about some pictures of this key, especially with the back open showing the battery? I guess there's a key out there I haven't seen...

 

Valvashon, this may be getting a little off topic for the r53 forum, as the following pertains to r56 Comfort Access Key,.. But this may answer your question anyway, and help future seekers who google up this thread.

The photo is the MINI r56 key.

This video link pertains to a BMW comfort access key, so the shape is different, but I'm willing to bet that other than the shape being different, everything else is the same for this r56 Comfort Access Key. I test drove an '07 MINI with this key, kinda cool the way the metal key slides out of it. Also, thanks for your post with diagram a few replies above here.

 

Nice write up on the first gen. CR2032 on the pre 7/2004. Then on the R56+ with comfort access only.



http://www.ecstuning.com/Search/SiteSearch/66126912985/



Below is the standard key from R56+ with no backing small cover for the key.



&

The the comfort access key which has the battery cover right on the back to replace the CR2032 battery. Its a small circular lid then the of the cover with a notch so you can snap it off. Then the battery sets into the cap or base and snaps back together.

When my key battery for the comfort access R56 stared to go I got the warning light on the dash.

Here is a pic from the 2013 manual.



And 2010.




Thanks and hope that helps with the comfort access , that all the info I have.

 

Thanks for this. That's the key I have.

 

What I was able to determine from realoem.com is that the rechargeable key (which you have to put in the slot of the dash) and the comfort access key (which can just ride around in your pocket) look virtually identical from the outside. Your only real clue would be to know if you have comfort access or not, correct?

Val