How to Replace the Battery in an Older Mercedes GLC350 Key?
3 Answers
The method to replace the battery in an older Mercedes GLC350 key is as follows: Slide open the tab at the rear end of the key to remove the mechanical key. Insert the mechanical key into the side slot of the key holder, press the internal gray button, and with the other hand, push the rear end of the key upward. When a gap opens, remove the mechanical key, then manually take out the rear end to replace the battery. After installing the new battery, reinsert the key holder. The older Mercedes GLC350E is an SUV with body dimensions of 4665mm in length, 1910mm in width, and 1650mm in height, and a wheelbase of 2875mm.
Last time camping, my teammate's GLC key fob stopped working, so I helped replace the battery on the spot. First, check the small switch on the back of the key—use your fingernail or a coin to slide it downward and pull out the mechanical key. Then, insert a flathead screwdriver into the gap in the middle of the plastic shell and gently pry it open, starting from the keyring end for easier leverage. Once opened, you'll see the silver coin cell battery, likely a CR2032 model—the battery cover can be lifted with a fingernail. When replacing, ensure the battery's positive side faces upward, and press the cover firmly until you hear a click to confirm proper installation. As a tip, if the rubber seal is aging, apply a bit of petroleum jelly to prevent water damage to the key.
My 2015 GLC350 had its battery replaced just last year. The actual operation was simpler than expected: After removing the mechanical key, the entire casing is actually secured by six plastic clips. Using an old credit card to slowly pry open along the casing seam is safer than metal tools, preventing surface scratches. Key point: When removing the battery, don't force it out—there's a small side clip; pressing it will make the battery pop up automatically. Before installing the new battery, it's best to clean the metal contacts in the battery slot with an alcohol-dipped cotton swab, especially since oxidation layers can form from prolonged friction when the key is kept in a bag.
