How to Save Money on Audi Battery Replacement Does your Audi key fob have trouble locking and unlocking? This could be a sign that the battery must be replaced. To replace the battery, simply open the metal key using a flathead and pop the back cover open using a screwdriver. https://autolocksmiths03567.blogdun.com/30619787/a-step-by-step-guide-for-choosing-the-right-audi-a4-spare-key