How to Save Money on Audi Battery Replacement Is your Audi key fob not locking and unlocking it? This could indicate that the battery needs to be replaced. To replace the battery, open the key made of metal using a flathead and pop the back cover up with the screwdriver. https://g28carkeys01931.therainblog.com/29275036/10-top-books-on-audi-a4-spare-key