Replace BMW Key Battery If your BMW key isn't able to open your car or turning over the engine, it may be time to replace your battery. Fortunately, it's a simple fix. All you have to do is remove the key fob cover then carefully remove and replace the battery, https://carkeyreplacements76584.pointblog.net/this-is-the-advanced-guide-to-bmw-3-series-key-fob-71935109