Replace BMW Key Battery It might be time to change your battery in the event that your BMW key won't open your car or turn off the engine. Fortunately, it's a simple fix. It's as easy as removing the key fob, then replace the battery and gently put it back. https://www-thekeylab-co-uk44503.activosblog.com/29451017/what-s-the-reason-bmw-key-fobs-is-fastly-changing-into-the-most-popular-trend-in-2023