How to Upgrade Your BMW Key 1 Series If your BMW keyfob isn't working well, you might need an upgrade to the battery. Also referred to a coin battery, these are easily obtainable and replaceable in just a few easy steps. Each fob is associated with an individual driver profile, https://auto-locksmith31467.blogdeazar.com/30846535/a-step-by-step-guide-to-selecting-the-right-bmw-battery-replacement-key