Replace BMW Key Battery If your BMW key isn't opening the doors of your car or turning over the engine, it might be time to replace your battery. It's an easy fix. Simply remove the key fob, then replace the battery, and then gently put it back. Follow these steps https://carkeyreplacement64138.isblog.net/15-interesting-facts-about-bmw-key-fobs-that-you-never-knew-47386534