How to Change the Battery in Your Mercedes-Benz Key Fob: A Step-by-Step Guide

by Phil Borges // in Car

Frequently Asked Questions

Replacing the Battery in Your Mercedes-Benz Key Fob

To replace the battery, follow these steps:

  1. Find the notch – Look for the small notch that allows you to pry the key fob apart.
  2. Pry it open – Carefully use a flathead screwdriver to separate the two halves.
  3. Identify the battery – Locate the battery type; usually, it’s a CR 2025 or CR 2032 coin battery.
  4. Remove the old battery – Use the screwdriver to gently pop the battery out.
  5. Install the new battery – Ensure the positive side faces the correct direction and snap it into place.
  6. Close the key fob – Align the two halves and press firmly until they snap together.

Identifying the Correct Battery for a Mercedes Key Fob

Use these steps to find the right battery:

  • Check the manual – Your owner’s manual should specify the battery type.
  • Examine the fob – The current battery type is usually printed on the battery itself.
  • Dealer advice – Mercedes dealers can also inform you of the correct battery.

Safe Mercedes Key Fob Opening Techniques

Opening without damage:

  • Use a purpose-made key fob tool or a flathead screwdriver.
  • Insert the tool in the notch and gently twist.
  • Avoid excessive force to prevent damage to the casing or internal components.

Expected Costs for Key Fob Battery Replacement

Cost elements:

  • Battery – The price is usually around $5 to $10.
  • Service fee – If a dealership or locksmith assists you, a service fee may be charged.

Troubleshooting Post-Battery Replacement Issues

If your key fob isn’t working:

  • Check battery orientation – Ensure the battery is facing the right way.
  • Clean contacts – Wipe the battery contacts with a clean cloth to ensure good contact.
  • Reset the fob – Some fobs may need resetting; consult your manual for instructions.

Handling a Depleted Key Fob Battery in a Mercedes

When the battery dies:

  • Use the physical key – There’s usually a metal key inside the fob for manual entry.
  • Battery replacement – Replace the fob’s battery as soon as possible.
  • Roadside assistance – If needed, Mercedes roadside assistance may help to access your car.

About the author, Phil Borges