How To Take Battery Out Of Mercedes Key Fob. The Smart Key uses two 3-volt CR 2025 batteries while the Chrome Key uses just one. The battery type for your Mercedes-Benz key fob should always be CR 2025.
Step 1 Release the metal key by sliding the black tab to the right. Then youll see a slot at the end of the key fob. Put the new battery in its place making sure that the new battery is facing the right way.
For the Smart Key pull the latch at the end of the key holder stick your key horizontally into the open slot and lift the battery compartment out to replace the batteries.
We strongly recommend using a Lithium battery like these ones as they last much longer. Pull until it releases. Step 2 Take the metal key out of the fob. Hold out your other hand to catch it as you pull the latch to avoid losing it.
