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 a simple fix. Simply remove the key fob, replace the battery, and then gently put it back. Follow these steps and https://www-thekeylab-co-uk90977.tinyblogging.com/why-you-should-concentrate-on-enhancing-bmw-3-series-key-fob-73879278