How to Upgrade Your BMW Key 1 Series If your BMW key fob isn't functioning well, it's likely that it needs an upgrade to the battery. These are also known as coin batteries and can be replaced with just a few steps. Each key is connected to a driver profile https://g2823931.thezenweb.com/what-is-bmw-battery-replacement-key-and-how-to-utilize-it-68597679