How to Save Money on Audi Battery Replacement Is your Audi key fob having trouble locking and unlocking? This could be a sign that the battery is in need of replacement. To replace the battery, turn off the metal key and use a flathead screwdriver to remove the back cover. https://autolocksmiths04400.jts-blog.com/29178111/how-audi-a4-spare-key-changed-my-life-for-the-better