2008 Mercedes C-Class Owner's Manual - Page 429

Practical hints Replacing SmartKey batteries If the batteries in the SmartKey/SmartKey with KEYLESS-GO* are discharged, the vehicle can no longer be locked or unlocked. It is recommended to have the batteries replaced at an authorized Mercedes-Benz Center. Warning! 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. G i When replacing batteries, make sure they are clean and free of lint. Batteries contain poisonous and corrosive substances. Therefore keep the batteries out of reach of children. If a battery is swallowed, seek medical help immediately. i When replacing batteries, always replace both batteries. The required replacement batteries are available at any authorized Mercedes-Benz Center. 1 Mechanical key 2 Battery compartment Insert mechanical key 1 into opening. Press mechanical key 1 in direction of arrow. The battery compartment is unlatched. Pull battery compartment 2 out of the housing. Replacement batteries: Lithium, type CR 2025 or equivalent. Remove the mechanical key from the SmartKey ( page 424). Warning! G SmartKey batteries contain Perchlorate material, which may require special handling and regard for the environment. Check with your local government's disposal guidelines. California residents, see http://www.dtsc.ca.gov/HazardousWaste /Perchlorate/index.cfm. 428