How to Save Money on Audi Battery Replacement Is your Audi key fob having trouble locking and unlocking it? This could be a sign the battery is in need of replacement. To replace the battery, turn off the metal key and use a flathead screwdriver to open the back cover. https://g2827265.ziblogs.com/29952016/the-reason-everyone-is-talking-about-audi-a4-spare-key-right-now