How to Save Money on Audi Battery Replacement Is your Audi key fob having difficulty locking and unlocking? This could be a sign that the battery is in need of replacement. To replace the battery, open the metal key with flathead, then pop the back cover up with the screwdriver. https://auto-locksmiths31995.alltdesign.com/10-unexpected-audi-a4-spare-key-tips-49843418