How to Change the Battery in a Mercedes Key Fob

If you are unable to unlock your Mercedes with the key FOB, the battery is probably dead. Changing the battery in your key FOB is not difficult. You can easily do it at home by following these steps.

Keep in mind that the key your Mercedes uses depends on its age. Older vehicles will use a smart key, which requires two batteries, and newer models use the chrome key, which uses a single battery.

Changing the battery in a Mercedes Smart Key FOB

1.) Slide the tab at the bottom of the FOB to release the key

2.) Push the key into the tab at the end of the fob

3.) Pull the battery carrier out of the bottom of the FOB

4.) Remove the batteries

5.) Install new batteries with both positive sides facing away from the buttons on the FOB

6.) Slide the battery carrier back into the FOB

7.) Check to make sure the FOB is working

On some Smart Keys, the batteries are not stacked on top of each other but positioned side by side.

Video Guide For Changing Batteries

Changing the battery in a Mercedes Chrome Key FOB

1.) Look in the empty key slot for a black plastic tab

2.) Using the key, push the tab in and up to release the battery panel

3.) Carefully remove the panel, exposing the battery

4.) Remove the old battery and install the new one

5.) Snap the battery cover back into place

6.) Check to make sure the FOB is working

Still having issues?

If your FOB is still having issues after replacing the battery, there may be another issue. If you are still having issues, give Alex’s Autohaus a call or schedule an appointment online. Our team of factory-trained technicians has the know-how to diagnose the issue you are having with your key FOB.