How to Save Money on Audi Battery Replacement Is your Audi key fob having trouble locking and unlocking it? This could be a sign that the battery is in need of replacement. To replace the battery, open the metal key using flathead, then pop the cover off using a screwdriver. https://g28carkeysolutions99556.blog2freedom.com/30059908/why-everyone-is-talking-about-audi-a4-spare-key-today