Tutorial on Replacing the Battery in an Older Mercedes-Benz CLS55-AMG Key

[JulietteLee]

Detailed instructions for replacing the battery in an older Mercedes-Benz CLS55-AMG key are as follows: 1. To replace the battery, first locate the button on the back of the key: After finding the button, press it and slide the back cover of the key forward to successfully open it. You will then see the battery in the adjacent slot. Open the slot, remove the old battery, and replace it with a new one. Next, reattach the back cover of the key to complete the battery replacement. 2. Pay special attention to the battery model when replacing the key battery: The remote key for Mercedes-Benz cars uses a 3V CR2025 battery, which can be purchased at stores. Also, note that the car remote key contains a battery that typically lasts 2 to 3 years. 3. Mercedes-Benz vehicles use two methods to indicate low key battery: One is when you press the ignition switch, the Mercedes dashboard will display a message to replace the key battery; the other is when you press the lock or unlock button on the key, if the indicator light on the key dims or does not light up, you should promptly replace the key battery.

[KiraFitz]

Last time I changed the key battery, I was also worried about damaging the casing, but it turned out to be quite simple. First, press the small button on the side of the key and pull out the metal part completely. Then use this metal piece to gently pry open the seam of the key casing. The older Mercedes key design is quite thoughtful—you can separate the upper and lower covers by following the seam. Inside, there's a silver coin-cell battery, model CR2025, which you can easily find genuine ones at supermarkets. When replacing, pay attention to the battery's polarity—place it with the printed side facing up. Finally, press the casing back together until you hear a click, indicating the clips are secured. The whole process takes no more than three minutes. After changing, remember to press the key buttons to test the window response. Regularly changing the battery can prevent the awkward situation of sudden power loss—I make it a habit to change it every two years.

[DiChase]

Replacing the battery is a DIY job—all you need is a coin. After removing the mechanical key, gently twist the coin in the groove along the key's edge, and the plastic shell will split in two. See that round battery in the center of the circuit board? Never pry it out directly with your fingers; using a small screwdriver to lift it from the side is safer. When installing the new battery, pay attention to the polarity markings on the sticker—installing it backward can fry the circuit. Last time I replaced mine, the remote range shortened, and I later realized fingerprints were left on the contacts during installation. A quick wipe with an alcohol swab fixed it. I recommend buying Panasonic or Sony batteries—off-brands tend to leak.

[McChloe]

Old car keys are pretty durable. I've disassembled mine over a dozen times. There's a small notch at the top of the key - just press your nail into it and pry upwards to open the casing. The battery compartment is under the rubber pad, so be careful not to lose it. While replacing the battery is simplest, some people bend the spring contact, which can actually be repositioned with a toothpick. Key point about battery type: use the universal 2025 model (20mm diameter), not 2032 - though it fits, the contact won't be good. After installation, don't rush to close the case; press the unlock button to check if the red light comes on. If there's no response, reopen and reinstall the battery. If the sealing ring is worn out, you can buy a new shell set on Pinduoduo for about 20 yuan.

[DonovanMarie]

Last time a friend asked how to replace the key battery, I recorded a video tutorial showing that even female car owners can get it done in three minutes. After pulling out the metal key, there's a fine seam at the plastic shell connection. Just pinch the upper and lower covers with your thumb and index finger, then pull them apart sideways—no tools needed. Note that the internal electronic components are fragile, so avoid touching them with metal tools. The battery model CR2025 is printed on the front, and the negative terminal should face downward during installation. Make sure the sealing O-ring stays dust-free, otherwise the key might let in water during rain. Once, I replaced the battery in a parking lot and found the key's lock function didn't work afterward. After reopening it, I realized the battery wasn't seated properly. I recommend buying a five-pack of batteries from JD.com's self-operated store—it's affordable and guarantees authenticity.

[MakaylaAnn]

I've replaced the battery in this key fob three times myself, with the cheapest one costing only five yuan. The key to opening the case lies in finding the right pressure point: there's a horizontal line below the Mercedes logo on the back of the key - just slide your fingernail along it to pop it open. The original battery has a Mercedes star logo on the back, but generic brands work fine too. Before installing a new battery, remember to check if the contacts are oxidized or blackened; a light rub with an eraser can improve sensitivity. Once after installation, I found the trunk button wasn't working - turns out there was a protective film on the battery's positive terminal that I forgot to remove. Nowadays, online battery kits even come with case-opening tools, making the process much more convenient than before.