How to Save Money on Audi Battery Replacement Do you notice that your Audi key fob experience difficulty locking and unlocking? This could indicate that the battery is in need of replacement. To replace the battery, open the metal key with flathead, then pop the cover off using a screwdriver. https://g28-car-keys26618.bleepblogs.com/30719268/what-s-the-fuss-about-audi-a4-spare-key