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How to replace batteries on any Key Fob Remote for Mercedes Benz


How to change the battery on the Mercedes Benz Smart Key Fob. How do you know you need a new battery? The remote lock or unlock range is poor. Or even worse, door lock/ unclock is not even working. These videos will show how to change the battery on different Mercedes-Benz Key Fob Remotes. There are several Mercedes Smart Key remotes so make sure to look at the correct video.

We strongly recommend using a Lithium battery like these ones, as they last much longer. 

First you need to identify which key you have. There are several models. The current Smart key fob is the chrome key with a triangle panic button.

If your buttons are worn out you may want to consider adding a silicone case to avoid further damage to your key. You can get a cover case for less than $10, see here. 

How to replace / change  Mercedes Key Fob Batteries

Step-by-Step Videos 

1. Current Chrome Key

mercedes new key fobTriangle Panic Button

It requires  ONE CR 2025 battery.



2. Chrome Key

mercedes round chrome keyRound panic button

Requires TWO CR 2025 batteries.
Make sure to get Lithium battery like these ones on Amazon.


3. Older Smart Key Fob mercedes key fob

Black Plastic Housing

Requires TWO CR 2025 batteries

4. First Model Smart Key Fob Remote 

mercedes first model smart keyOldest Smart Key Black Plastic Housing

Requires two TWO CR 2025 batteries


Here is one long video where we show how to replace the batteries in any of the Smart Key Fobs made by Mercedes Benz.


  1. 2005 Vito van. What battery type do I require .? Many thanks

  2. I was mugged and my car keys for mercedes e-class kompresor car however i have a spre key which is working i wonder the other they stole can be deleted so they cant use it

  3. i replaces battery for remote key for Mercedes e 320 work only for a week replace battery again not work at all !!! what is next step please

    • Sounds like you have a defective key. Do you have a spare key to test? Also does the key start the car? Each key has to functions (circuits) one to unlock the car and the second to start it. For the most part they are independent of each other. That’s why a dead key should still be able to start the car.

  4. I changed my batteries in my key fob (the one with the round panic button) and at first it worked immediately, but now it works periodically and my car alarm randomly goes off even if I haven’t been in the car for several hours! What’s wrong??

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