What is the tutorial for replacing the battery in an old Mercedes-Benz E-Class key?

[ChristopherMarie]

The tutorial for replacing the battery in an old Mercedes-Benz E-Class key is as follows: 1. First, take out the key and dismantle it; 2. Then, flip the remote key to the back, slide the black button, pull out the mechanical key, insert the mechanical key into another hole, and gently squeeze it. The back cover of the remote key will pop out by itself; 3. Use a toothpick or needle to pick out the old battery, or repeatedly tap the remote key in the palm of your hand until the old battery falls out; 4. Install a new CR2025 button battery, then reattach the back cover and mechanical key in order. The Mercedes-Benz E-Class is a mid-to-large-sized high-end business sedan, coupe, and station wagon developed by Mercedes-Benz, positioned between the C-Class and S-Class. In terms of body dimensions, the Mercedes-Benz E-Class measures 5026mm in length, 1854mm in width, and 1477mm in height, with a wheelbase of 3014mm.

[DePeter]

I once replaced the battery for an older Mercedes-Benz E-Class key fob, and it felt quite simple. This type of key usually has a folding mechanical part—first, locate the small button on the side, press it, and pull out the mechanical key. Next, use a small flathead screwdriver or a coin to gently pry open the cover at the rear or side groove of the key fob, exposing the battery compartment. Be careful not to use too much force, as the plastic can crack easily. The old battery is typically a CR2025 or similar model—I bought one from a supermarket for just three yuan last time. After removing the old battery, insert the new one, making sure the positive side faces upward. Close the cover firmly and reinsert the mechanical key. Test the remote locking and unlocking functions to ensure they work properly. Sometimes, if the cover isn’t secured well, it might fall off, so I’d advise being careful to avoid losing it. The whole process takes less than ten minutes, and doing it yourself can save over a hundred yuan compared to going to a repair shop—totally worth it. Just make sure the battery matches correctly, and there won’t be any issues.

[JaylaAnn]

As someone who frequently repairs cars, I often replace the battery in my old E-Class key. Most of these key models feature a folding design—first press the side button to release the mechanical key and pull it out. On the back of the key, there's a small cover, which I usually pry open gently at the seam using a plastic pry tool or my fingernail. Inside, you'll find a button battery, model CR2025—make sure not to confuse it with other sizes. When removing the old battery, avoid touching the metal parts to prevent static electricity from damaging the circuit. Install the new battery with the positive (+) side facing up. Then, snap the cover back into place with a click, and finally test the remote's response. If it still doesn't work after replacement, the issue might be an improperly secured cover or poor battery contact—just recheck and adjust. The key to the whole process is gentle handling—avoid forcing anything to prevent damaging the plastic clips. This method is safe and worry-free, helping you avoid the awkward situation of a suddenly non-functional key.

[LandonMarie]

Changing the battery is quite simple, I've done it myself. The older E-Class key has a mechanical part—just press the small hole to pop out the small key. Pry open the cover from the gap on the key body to reveal the battery compartment. Remove the old battery and replace it with a new CR2025 or similar model, which costs just a few dollars at the supermarket. Close the cover, reinsert the small key, and test the locking function. Make sure the battery is placed with the positive side facing up. It only takes a few minutes—don't overcomplicate it, it's quick and convenient.

[RyleeRose]

I think changing the battery can be done by oneself. Once, my old E-Class key ran out of power. First, locate the side button, press it, and pull out the mechanical key part. Then, look for the groove on the main body of the key, and gently pry open the top cover with a screwdriver or a coin. Inside, the battery is a round CR2025 model. Take it out and replace it with a new one, ensuring the positive side faces the logo direction. Close the cover and reinsert the mechanical key to test the remote. That time, I didn't close the cover tightly and it almost fell off, so I recommend everyone to be steady and not rush. As long as the battery matches correctly, the whole process is problem-free. After testing the lock, everything worked normally for safe driving.

[OKendra]

Ensuring the car key functions properly is crucial, and I have replaced the battery myself. The older E-Class keys typically have a small hole button; pressing it allows you to remove the mechanical key. The back of the key body has a cover, which can be gently pried open to reveal the internal battery compartment. Remove the old CR2025 battery and replace it with a new one, ensuring the positive side faces upward and is properly aligned. Reattach the cover and press firmly to test the locking function. Wearing gloves during the operation helps avoid static electricity interference with the circuit, and buying the same battery model prevents failure. This method is simple, safe, and ensures no disruption to your travel plans.