How to Save Money on Audi Battery Replacement Does your Audi key fob have issues locking and unlocking? This could indicate that the battery is in need of replacement. To replace the battery, simply open the metal key using a flathead and pop the back cover open using the screwdriver. https://g2818877.mpeblog.com/53997498/what-is-audi-a4-spare-key-and-why-is-everyone-speakin-about-it