How to Replace the Remote Control Battery for a Mercedes-Benz Car?
3 Answers
From the tail end of the key, push up the marked switch, and the hidden mechanical key will pop out slightly. Then, you can remove the mechanical key. Next, from the tail end of the key, use the mechanical key you just took out to press against the marked position. Apply a slight force, and the key shell will open. After removing the key shell, insert any object into the gaps on both sides and gently pry to remove the old battery. Then, install the new battery.
Last time I changed the battery in my Mercedes key fob, it was pretty quick. First, you need to confirm the key model—most Mercedes keys use CR2025 coin batteries. Get a small Phillips screwdriver; there are one or two tiny screws on the back of the key casing. Unscrew them gently so you don’t lose them. Pry open the casing to access the battery compartment. The old battery might be placed positive-side up or down—check the markings inside (if you’re unsure, take a photo to remember the orientation). Remove the old battery, clean any dust from the slot, and insert the new battery in the correct direction. Close the casing and screw it back together slowly to avoid damaging the circuit board. Finally, test if the buttons light up—if not, the battery might be inserted backward or the contacts aren’t secure. The whole process takes about 3–5 minutes. Washing your hands beforehand to prevent static is safer. I recommend buying genuine batteries on Amazon—they’re cheaper.
I often change the battery of my Mercedes key myself to save the cost of going to the dealership. Prepare a new CR2025 battery—the key casing usually has clips or screws (older models mostly have screws, newer ones have clips). Carefully pry open the edge with a fingernail or small knife, but don't use too much force to avoid breaking it. Check the markings in the battery slot—just make sure the positive side faces up. The old battery can be easily popped out. Replace it with the new one and ensure it's firmly inserted. Press the casing back until you hear a click. After finishing, test the lock and unlock buttons—if they respond quickly, you've succeeded. If not, check the battery contacts; they might be oxidized, so clean them if necessary. Keep a couple of spare batteries in your car so you won't panic if the remote fails. Before starting, watch video tutorials a couple of times.
