How to Save Money on Audi Battery Replacement Is your Audi key fob not locking and unlocking? This could be a sign that the battery is in need of replacing. To replace the battery, open the key made of metal and use a flathead screwdriver to remove the back cover. https://g28carkeys96202.blogzet.com/comprehensive-list-of-audi-a4-spare-key-dos-and-don-ts-44870910