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, simply open the metal key using a flathead and pop the back cover open using a screwdriver. https://g28-car-keys13069.blog-eye.com/29912652/10-unexpected-audi-a4-spare-key-tips