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 must be replaced. To replace the battery, open the key made of metal using an flathead and then open the cover off using the screwdriver. https://car-locksmith73359.tribunablog.com/audi-a4-spare-key-tips-that-will-transform-your-life-44388721