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

[SanCody]

First, flip open the tab at the rear end of the key to remove the mechanical key. Insert the mechanical key into the slot at the tab position, apply slight force, and the back cover will open. Then, take out the depleted old battery, replace it with a new one, close the back cover, and the key battery replacement is complete.

[DeRuth]

When I was driving my Mercedes-Benz GLB, the key battery died, and the remote unlocking was always unreliable. After checking, I found out the battery was depleted. Changing it myself was super easy—I just used a credit card to gently pry open the key from the edge gap, avoiding metal tools to prevent scratching the plastic shell. Inside, the battery was a CR2032. I removed the old battery, noted the correct orientation, and installed the new one with the positive side facing up. Finally, I pressed the cover firmly and tested the key—it worked perfectly again. The whole process took less than 5 minutes and saved me a trip to the dealership. A good tip: if the remote range shortens, it’s a sign to replace the battery. Buying the same battery model at a supermarket is cost-effective. Also, avoid exposing the key to high temperatures to extend battery life to two or three years—truly a handy little skill.