391 Practical hints
Replacing SmartKey batteries
Replacing SmartKey batteries
If the batteries in the SmartKey are 
discharged, the vehicle can no longer be 
locked or unlocked. It is recommended 
to have the batteries replaced at an autho-
rized Mercedes-Benz Center.Batteries contain materials that can harm 
the environment if disposed of improperly. 
Recycling of batteries is the preferred 
method of disposal. Many states require 
sellers of batteries to accept old batteries 
for recycling.SmartKey
Replacement batteries: Lithium, type 
CR 2025 or equivalent.
Remove the mechanical key from the 
SmartKey (
page 387).
1Mechanical key
2Battery compartment
Insert mechanical key1 into opening.
Press mechanical key1 in direction of 
arrow.
Battery compartment2 is unlatched.
Pull battery compartment2 out of the 
housing.
Warning!G
Batteries contain poisonous and corrosive 
substances. Therefore keep the batteries 
out of reach of children.
If a battery is swallowed, seek medical help 
immediately.
iWhen inserting the batteries, make sure 
they are clean and free of lint.
iWhen replacing batteries, always replace 
both batteries.
The required replacement batteries are available 
at any Mercedes-Benz Center.