Replace BMW Key Battery If your BMW key isn't opening the doors of your car or turning over the engine, it may be time to change your battery. It's a simple fix. It's as easy as removing the key fob, then replace the battery, and then gently put it back. https://www-thekeylab-co-uk19844.ziblogs.com/30251163/what-bmw-key-fobs-experts-would-like-you-to-learn