How to Save Money on Audi Battery Replacement Is your Audi key fob having difficulty locking and unlocking? This could indicate that the battery must be replaced. To replace the battery, open the key made of metal and use a screwdriver with a flat head to open the back cover. https://g28carkeys59787.wizzardsblog.com/30159590/15-shocking-facts-about-audi-a4-spare-key-you-ve-never-heard-of