Important safety notes

It is advisable to have batteries replaced at a qualified specialist workshop, e.g. at an authorized Mercedes-Benz Center.

WARNING  
Batteries contain toxic and caustic substances. For this reason, keep batteries out of the reach of children.
If a battery has been swallowed, seek medical help immediately.

WARNING  
The SmartKey batteries contain perchlorate material, which may require special handling and regard for the environment. Observe government disposal guidelines. California residents, see www.dtsc.ca.gov/HazardousWaste/Perchlorate/index.cfm.

Checking the battery

► Press the button.

The SmartKey battery is working properly if battery check lamp 1 lights up briefly.

If battery check lamp 1 does not light up briefly during the test, the SmartKey battery is discharged.

► Changing the battery

The battery can be obtained from any authorized Mercedes-Benz Center.

If the SmartKey battery is checked within the signal reception range of the vehicle, pressing the button locks or unlocks the vehicle.

Changing the battery

You require a CR 2025 3 V cell battery.

► Take the mechanical key out of the SmartKey.

► Press mechanical key 2 into the opening in the SmartKey in the direction of the arrow until battery tray cover 1 opens.

When doing so, do not hold cover 1 shut.

► Remove battery tray cover 1.

► Repeatedly tap the SmartKey against your palm until battery 3 falls out.
► Insert the new battery with the positive terminal facing upwards. Use a lint-free cloth to do so.
► Make sure that the surface of the battery is free from lint, grease and all other forms of contamination.
► Insert the front tabs of battery tray cover 1 and then press to close it.
► Insert the mechanical key into the SmartKey.
► Check the function of all SmartKey buttons on the vehicle.