How to Replace the Battery in a Mercedes-Benz S350 Key?
2 Answers
The back of the Mercedes-Benz S350 key has a button. Press this button and slide the key's back cover forward to open it. The battery is located in the slot nearby. During the replacement process, it is crucial to pay attention to the battery model. Most Mercedes-Benz key batteries are model 3V-CR2025. After removing the old battery from the slot, replace it with a new one. Then, reattach the key's back cover. Once installed, the battery replacement is complete. When the key battery is low, the Mercedes-Benz vehicle will provide two types of alerts: 1. Ignition Switch: Press the ignition switch, and the dashboard will display a message to replace the key battery. 2. Lock Button: Press the lock or unlock button on the key. If the indicator light on the key dims or does not light up, it is time to replace the key battery.
I've been driving a Mercedes S350 for several years, and changing the key battery is something I can easily do myself—it's quite simple. First, hold the car key in your hand; there's usually a small groove or gap on the back. Gently pry open the casing with a small screwdriver or plastic pry tool, being careful not to damage the plastic shell with too much force. Once opened, you'll see a small battery inside. Mercedes keys typically use a CR2032 coin cell battery. Before removing the old battery, note the orientation of the positive and negative poles. When installing the new battery, make sure the positive side faces upward. Close the casing and press it lightly to secure it, then test the remote locking and unlocking functions to ensure they work properly. If there's no response, the battery might be inserted backward or there could be poor contact—check and try again. The whole process takes about five minutes and saves you a trip to the dealership. If you find it troublesome, you can always ask a professional technician for help, but I recommend checking the key battery level regularly to avoid sudden failure affecting usage. You can buy the battery at supermarkets or online—opt for reputable brands to avoid counterfeit products. Remember to keep your hands clean during the process to prevent grease from interfering.
