Replace BMW Key Battery If your BMW key isn't able to open your car or turning on the engine, it might be the time to replace your battery. It's simple to fix. You simply need to remove the key fob, then replace the battery, and then gently put it back. https://carkeyreplacements39458.blog-eye.com/30316474/it-s-time-to-expand-your-bmw-key-fobs-options