How to Save Money on Audi Battery Replacement Is your Audi key fob having difficulty locking and unlocking? This may be a sign that the battery must be replaced. To replace the battery, you must open the metal key with flathead, then pop the back cover open using the screwdriver. https://carlocksmith43789.blogsvila.com/29952355/what-is-the-audi-a4-spare-key-term-and-how-to-use-it