Tutorial on Replacing the Battery for an Older Mercedes-Benz R350L Key

[AnastasiaDella]

Mercedes key batteries typically last about two years, while original factory batteries can last up to six years. When the key battery is low, the Mercedes vehicle will alert us in two ways: first, when we press the ignition switch, the dashboard will display a message to replace the key battery. Second, when we press the lock or unlock button on the key, the indicator light on the key will dim or stop lighting up, signaling that it's time to replace the battery. Below are the steps to replace the battery in an older Mercedes-Benz GLA key: 1. Slide open the tab at the back of the key to remove the mechanical key. 2. Insert the mechanical key into the side slot of the key, press the internal gray button, and with the other hand, push the back end of the key upward. When a gap opens, we can remove the mechanical key. 3. Then, manually remove the back end to access and replace the battery.

[DelEvan]

I remember dealing with a key battery replacement for an older Mercedes-Benz R350L before, and the process was quite straightforward. Start with the key's design: it usually has a folding mechanism—press a button to release the metal part, then locate the notch along the side seam. Use a thin screwdriver or coin to gently pry open the casing (avoid excessive force to prevent cracking). Inside, you'll find a CR2032 coin cell, a common type. When removing the old battery, note the positive side facing up and remember its position—install the new battery the same way to ensure proper contact. Close the casing, press firmly, and test if the key's indicator light works. Replacing the battery every two years helps prevent mid-failure. A tip: use reputable brands like Sony to avoid leakage issues. Why DIY? A dealership might charge hundreds, while doing it yourself costs just a few bucks—saving both money and time.

[BradyLee]

I replaced the battery in my Mercedes R350L key last year, and it was quite simple. First, prepare a new CR2032 battery, which can be found in most supermarkets for just a few bucks. Extend the key and locate the small gap on the side. Use a fingernail or coin to gently pry open the casing—don’t yank it hard to avoid scratches. Remove the old battery, noting which side faces up (usually the shiny side), then insert the new battery the same way, ensuring it’s secure. Press the cover back firmly, then stand near your car and test the lock button. If it doesn’t respond, try starting the car manually—sometimes a quick sync is needed. Key battery life depends on usage frequency; for frequent drivers, an annual replacement is normal. DIY saves money and time—I got it done in five minutes, much better than waiting in line at a shop.

[OGianna]

Here's how to replace the battery step by step: First, take out the key and press the folding button to open it. Then, gently pry open the key casing along the seam using a small tool like a toothpick or flat-head tweezers - avoid using a blade as it may cause damage. Inside, you'll find a CR2032 battery; remove it and replace it with a new one of the same model, ensuring the positive side faces upward. After placing the new battery, close the casing and press firmly to secure it. Test the buttons to ensure they work properly and the light turns on. Take your time during the process to avoid losing small components. This simple task can save you dozens of dollars by doing it yourself.