I have a 2005 r53 and the key batt I think needs replacement. It is not operating the lock or unlock system. The spare key does. I have used it in the car to charge it up but to no avail. has anyone here replaced the batt in one of these and what are the pit falls? how long do you have when changing the batt over and what is the procedure to get it talking to the car again.

 

I have a 2003MCS and the battery was a 2032. You simply pry open the key (there are a lot of threads with pictures) and replace the battery. I have heard some say that theirs was rechargeable but mine was not and I am not sure about yours. But if it does have the 2032 then it is NOT rechargeable and requires replacement.

With the new battery it will simply work. No programming or pairing required.

///Rich

 

If you do a search, I think you will find that the key on an '05 is not designed to be opened. Some people have cut them apart. The ignition is supposed to recharge the keys; I rotate my keys to keep them charged. Batteries don't last forever though; looks like a bad design to me. There are some old threads you can look up about this issue.

 

If you get the key open (when you determine the battery is nolonger accepting a charge), use thecmarking on the battery to crackdown a new rechargeable battery...at one point somebody did this...I.'m assuming they used google...think they got the batterys from a supplier in Tiawaian....they are NiMetalHydride I think....
When you do this rather than buying a new key, you will be one of the first!! So you should be pretty handy, resourceful, and if all else fails, it will still work as a regular key!!

 

Thank you for that.On looking at the key it does appear to not come apart. I did change them over and all was well till one just stopped working. I'm not 100% but my pick on it is that the batt has just given out. I suppose there is a chance that it has faulted in some way and it needs to be reprogrammed. This is now the easiest option for me can someone tell me how this it done.

 

The key is not desgined to open...
It is made to snap togeater once, and stay that way.
To open it, you are doing something it is not made to do...
Be careful, pry it open...any marks you leave will be there forever!
If you break-it, scratch it, deform it, you get to live with it!
You could buy a used 05+ gen1 eBay key to practice on....heck the battery might have a few recharges left in it!! Nobody said being first would be easy!!

 

Wolfson, I tried to replace the battery but it did not unlock the my car. I have 2004 Cooper S build 4/2004. I followed the directions in the manual but it onlys works when I am inside the car but the windows does not come down. When I am outside the car, nothing works. ANY IDEA

 

Try reprogramming the remote: https://www.northamericanmotoring.co...ogramming.html

 

OK for the 2005 mini cooper s which I have, my first suggestion is if the key fails to work and you feel that the batt has been charged by rotating the use of the two keys, before trying to open it, try initialising it first I did not do this but now wished I had as I will explain further on, I cannot be sure but mine just stopped working and being the 2ND key I was trying to use it to charge the batt. Maybe when a batt starts running down in voltage the key will just have to be used closer to the vehicle suggesting that it is running flat. Mine just stopped working completely. So I opened it using a fret saw on the key end to give me room to put a small screwdriver in and pry it open. on checking the voltage it appeared that the batt was OK. But as I had it open I replaced it with a new one then glued it back together. I then initialised both keys and all is well. If you have two keys you must do both at the same time as if you do one the other will not work. I am now wondering if by some strange happening, the key which I carry in my pocket somehow reinitialised itself. Which would account for the 1st key still working and 2ND key which I was using at the time just stopped working. Given all that I'm now back to the original position of both keys working again. I hope you can understand my rambling but if you cannot I will be only to happy to answer your questions. I have a series of photos of the batt replacement procedure but I do not know how to up load them.

 

Thanks for your reply. On my 2004 Cooper S, I have tried four new batteries on my key and still it only works when I point it next to the rear view mirror. My technician thinks it might be the module in the rear view mirror that is going bad. Also, the problem is that I can not find my spare key to test.

 

Please remember folks....
There are 2 different keys....
Very different.....
the early gen 1 mini...start of production to 2004, and then the 2005+ keys...
the early keys are made to have the batteries replaced......
the 2005+ keys are supposed to recharge in the car....and are not made to be replaced...anything is possible...