How To Change Mercedes Key Battery: Easy Step -By-Step Guide

How to Change Mercedes Key Battery

Table of Contents

How to Replace Mercedes Key Battery

If you own a Mercedes, the fob key that unlocks the car starts the engine and controls other features such as windows and trunk may be familiar to you. Unfortunately, just like any other battery-operated device, its battery drains over time – necessitating replacement.

In this article, we’ll show you how to replace that battery in your Mercedes key safely and conveniently.


Step 1: Purchase a replacement battery

The initial step in replacing your Mercedes key is to purchase a replacement battery. You can get this from either an authorized Mercedes dealership, auto parts store or online. Make sure you get the correct type of battery for your key – usually either CR2025 or CR2032).


Step 2: Remove the Key

To change a Mercedes key, you’ll need to open the key. Locate the small button on the back near where the key rings. Press this button and pull out a metal key with it. Use that metal key gently pry open the housing of the key without damaging either it or its housing.


Step 3: Disconnect the battery

Once the key has been opened, you will discover the battery. Use a small flathead screwdriver or similar tool to carefully take the battery from its housing. If necessary, gently wiggle the screwdriver until it’s loose.


Step 4: Install the new battery

Now that the old battery has been taken out, it’s time to insert the new one. Be sure to insert it with its positive (+) side facing up; you should hear a small click when it clicks into place.


Step 5: Reassemble the key

Once your new battery has been installed, it’s time to reassemble your key. Snap together the housing of the key and ensure it snaps into place securely. Finally, insert the metal key and press it until it clicks securely into place.


Step 6: Verify the Key

Once everything has been assembled, test it to ensure it functions correctly. With the key, you should be able to unlock doors, start the engine, and operate other features with ease.


Change Mercedes Key Battery


Additional Tips

  • If your Mercedes key does not function after replacing the battery, reprogramming may be required by either a dealership, professional locksmith, ask a Mercedes mechanic online for advice.
  • Additionally, avoid touching the new battery with bare hands as this could cause it to discharge faster.
  • Always properly dispose of old batteries and avoid throwing them away in the trash. If possible recycle them locally.



Changing the battery in your Mercedes key is an easy process that you can do yourself with the appropriate tools and replacement battery. However, if any difficulties arise or your key doesn’t function after replacing it, it is recommended to seek professional assistance. Keep your key charged for convenient remote access to all of your car’s features.


FAQs (Frequently Asked Questions)

How Often Should I Replace the Battery in My Mercedes Key?

Your Mercedes key’s battery should be changed every 2-3 years, depending on usage.

How much will it cost me to replace the battery for my Mercedes key?

Prices for replacement Mercedes key batteries vary depending on where you purchase them but typically range from $5 to $15.

Can I still use my Mercedes key if the battery is low?

Your key may still work temporarily, but eventually, cease working altogether. Therefore, replacing the battery as soon as possible is recommended to avoid any inconvenience.

How can I tell which battery type to use in my Mercedes key?

Usually, the type of battery used in your key can be found on its back. If not, refer to your owner’s manual or ask a dealership for assistance.

Do I Need to Reprogram My Mercedes Key After Replacing the Battery?

If your Mercedes key won’t function after replacing its battery, it may require reprogramming by either a dealership or a professional locksmith.

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