How to Replace a Dead Battery in a Mercedes Car Key?
3 Answers
To replace a dead battery in a Mercedes car key, follow these steps: 1. Flip the key to the back and push the button to pull out the mechanical key; 2. Use a flat-head screwdriver to pry open the gap at the tail of the key to open the key shell; 3. Remove the old battery and replace it with a new one; 4. After confirming the battery is properly installed, close the shell and reinsert the mechanical key. Mercedes-Benz models include: Mercedes GLS, Mercedes GLE, Mercedes GLC, Mercedes GLA, Mercedes CLA, etc. Taking the 2021 Mercedes GLS as an example, it is a mid-to-large-sized car with body dimensions of length 5214mm, width 1956mm, height 1823mm, and a wheelbase of 3135mm.
A few days ago, my Mercedes car key suddenly stopped working, and I realized the battery was dead. Replacing it myself turned out to be super easy. First, check the key model—most use a CR2032 coin battery, which you can buy for a few bucks at the supermarket. There's a small groove in the middle of the key; use a plastic pry tool or a coin to gently open the casing—Mercedes designed it quite user-friendly, no screwdriver needed. Once open, be careful not to damage the internal circuitry. Simply remove the old battery, noting the positive and negative orientation. Insert the new battery, place it back as it was, and close the cover until you hear a click, indicating it's locked. Then, press the remote buttons to test the lock/unlock functions—if they work, you're done. The whole process takes less than 5 minutes, saving you a trip to the dealership and over a hundred bucks. It's recommended to check the battery every two years, and keep a spare in the car just in case, especially in winter when cold weather drains batteries faster. Mercedes keys aren’t very waterproof, so avoid storing them in damp environments. This DIY trick is both cost-effective and reassuring.
I often help friends replace car key batteries, and the Mercedes model is particularly convenient. Preparation tools: a new CR2032 battery and a plastic pry tool—avoid using metal tools to prevent short-circuiting the key's circuitry. Use the pry tool to gently open the groove on the back of the key; most newer Mercedes models don’t have screws and can be opened directly. When removing the old battery, be careful not to damage the slot structure. After inserting the new battery, ensure good contact. Once replaced, firmly press the casing back into place and immediately test the remote response. If it occasionally malfunctions, try repeating the operation within 10 seconds near the car door or check if the battery contacts are oxidized and clean them. To prevent sudden battery failure, make it a habit to check the battery voltage every six months and always keep a spare battery in the car. Mercedes key batteries typically last about 2 years—choose reputable brands to avoid leakage damage. Overall, the maintenance is time-efficient and hassle-free.
