Replace BMW Key Battery It might be time to change your battery if your BMW key isn't able to open your car or turn on the engine. Fortunately, it's an easy fix. Simply remove the key fob, then replace the battery, and then gently put it back. Follow these steps https://thekeylab-co-uk77390.blogitright.com/30272523/why-everyone-is-talking-about-bmw-key-fobs-today