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 replacement. To replace the battery, open the key made of metal using a flathead and pop the cover off with the screwdriver. https://carlocksmith35745.mybuzzblog.com/9401491/everything-you-need-to-know-about-audi-a4-spare-key-dos-and-don-ts