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 is in need of replacement. To replace the battery, simply open the metal key with flathead, then pop the back cover open using a screwdriver. https://g28carkeys81761.blogs-service.com/61078251/it-s-the-perfect-time-to-broaden-your-audi-a4-spare-key-options