Description Reviews The Energizer CR2032 will fit all of the MINI keys, but there will be several problems you can run into so please read on. This is a direct replacement for all Gen 3 cars, it just takes a small screwdriver and a few mins of your time. This is also a direct replacement battery for all gen 2 cars R55-R61, but there is only a battery door on cars with comfort access to make it a super easy replacement. Officially for any other keys (non comfort access gen 2 and all gen 1 keys R50-R53) the batteries are not replaceable. Some gen 1 batteries also have a tab and a wire off of it, so that makes things even harder. We have had many owners carefully cut open their keys to replace the batteries. Make sure you diagnose the correct issue with your car before cutting open keys and having other possible issues. New keys cost $150 and up and are dealer-only items.