How to Save Money on Audi Battery Replacement Is your Audi key fob not locking and unlocking it? This could indicate that the battery is in need of replacing. To replace the battery, you must open the metal key with flathead, then pop the back cover open using the screwdriver. https://g28-car-key-solutions37385.blogdemls.com/29640532/why-all-the-fuss-about-audi-a4-spare-key