How to Replace the Battery in a Mercedes-Benz SL Key?

[LaKing]

There is a button on the back of the key. Press this button and slide the back cover forward to open the key. The battery is located in the adjacent slot. Open this slot, remove the old battery, and replace it with a new one.

[ValeriaRose]

As a maintenance technician who frequently handles automotive parts, my experience with replacing the battery in a Mercedes SL key is to carefully pry open the key's back cover. The key usually has a small gap, and you can gently lift it with a small screwdriver or plastic pry tool—don't use too much force to avoid damaging the casing. Remove the old battery (typically a CR2032 model), making sure to note the positive side facing up, then insert the new battery. After closing the cover, test the remote function to ensure it works properly. I also recommend checking the battery life regularly, generally replacing it every 1-2 years to avoid key failure when you're out. If the key gets wet or corroded, first dry the contacts with a cotton swab. When buying a battery, choose a reputable brand—it only costs a few dollars and can be easily found at a supermarket.