Replace BMW Key Battery If your BMW key isn't able to open your car or turning on the engine, it may be time to replace your battery. Fortunately, it's a simple fix. Simply remove the key fob, then replace the battery, and then gently put it back. Follow these steps https://car-key-replacement63588.alltdesign.com/what-to-look-for-to-determine-if-you-re-in-the-right-place-to-bmw-key-fobs-49883546