How to Replace the Battery in an Older Mercedes-Benz R320 Diesel Key?
3 Answers
Here is the method to replace the battery in an older R320 diesel key: 1. Push open the tab at the rear end of the key to remove the mechanical key. 2. Insert the mechanical key from the side of the key slot and press the internal gray button. 3. With the other hand, push the rear end of the key upward. When a gap appears, you can remove the mechanical key. 4. Use your hand to take out the battery from the rear end, and then you can replace the battery. After installing the new battery, reinsert the key bracket, and the key battery replacement is complete. The lifespan of a Mercedes key battery is generally two years, while the original factory battery can last up to six years. When the key battery is low, the Mercedes vehicle will alert us in two ways: one is that when we press the ignition switch, the dashboard will display a message to replace the key battery. The second is when we press the lock or unlock button on the key. If the indicator light on the key dims or does not light up, it's time to replace the key battery.
My old Mercedes R320 diesel edition key has been in use for several years. Recently, when the remote control range became shorter, I knew the battery was running low. I've replaced it myself twice, and it's quite simple. First, flip the key over and locate a small gap on the back. Use a small coin or nail clipper to gently pry open the shell. Inside is a battery compartment holding a CR2032 battery. Remember not to confuse the positive and negative poles—usually, the positive side faces up when removing it. After discarding the old battery, insert the new one of the same model, align it properly, press it firmly, and then gently close the shell until you hear a click, indicating it's securely locked. Finally, test the remote to lock and unlock the doors to see if the response is quick. I learned this trick from a forum—replacing it once a year prevents issues, avoiding the frustration of not being able to open the door at critical moments. It saves money, hassle, and even hones your DIY skills.
Replacing the battery for an older R320 diesel version key? I've done it a few times, not difficult. There's usually a small notch on the back of the key, just pry it open with a thin tool or your finger. The battery is a CR2032, very common, buy a new one from a hardware store and replace it, making sure the positive and negative poles match. I once installed it backwards, the remote didn't work for half a minute, but it was fine after readjusting. Don't pry the shell too hard, the plastic can crack easily. After replacement, the key response will be much faster. By the way, if the battery needs frequent replacement, it might be due to dirty internal contacts, just clean them. Regular replacement can extend the key's lifespan and reduce trips to the repair shop.
