Has any body had any luck in replacing the non-replaceable battery in the remote key in a 2004 cooper s?

 

I believe 2002-2004 had a replaceable battery, and 2005-2006 had a rechargeable battery which charged when the key is in the ignition.

You should have be able to pop the back of your fob open and get a new battery at any place which sells those flat watch type batteries.

 

The car is late 2004 so the battery is supposed to charge in the ignition but only if you drive longer that 30 mins (I don't). The key has to be cut open to get access to the battery. BMW Australia wants $600 to replace the key , they say the battery can not be replaced.