How to Save Money on Audi Battery Replacement Is your Audi key fob having difficulty locking and unlocking? This could be a sign that the battery is in need of replacement. To replace the battery, turn off the metal key and use a flathead screwdriver to remove the back cover. https://g2847115.kylieblog.com/30310951/is-audi-a4-spare-key-as-crucial-as-everyone-says