2005 Mercedes C-Class Owner's Manual - Page 344

Practical hints 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 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. i When inserting the batteries, make sure they are clean and free of lint. i When replacing batteries, always replace both batteries. The required replacement batteries are available at any Mercedes-Benz Center. G Keep the batteries out of reach of children. If a battery is swallowed, seek medical help immediately. 342