2011 Mercedes C-Class Owner's Manual - Page 76
2011 Mercedes C-Class Manual
Page 76 highlights
74 SmartKey SmartKey battery Important safety notes It is advisable to have batteries replaced at a qualified specialist workshop, e.g. at an authorized Mercedes-Benz Center. i You can obtain a SmartKey battery at any authorized Mercedes-Benz Center. i If the SmartKey battery is checked within signal range of the vehicle, pressing the & or % button results in the vehicle being locked or unlocked respectively. Changing the battery You require a CR 2025 3 V cell battery. X Take the mechanical key out of the SmartKey (Y page 73). Opening and closing G Warning! Batteries are toxic and contain caustic substances. For this reason, keep batteries out of the reach of children. If a battery has been swallowed, visit a doctor immediately. G Warning 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 www.dtsc.ca.gov/ HazardousWaste/Perchlorate/ index.cfm. Checking the battery X Press mechanical key ; into the opening in the SmartKey in the direction of the arrow until battery tray cover : opens. Do not hold the cover closed while doing so. X Press the & or % button. The SmartKey battery is working properly if battery charge indicator lamp : lights up briefly. X X If battery charge indicator lamp : does not light up briefly during the test, the SmartKey battery is discharged. X Replace the SmartKey battery (Y page 74). Remove the cover of the battery tray. Repeatedly tap the SmartKey against your palm until battery = falls out. X Insert the new battery with the positive pole facing upwards. Use a lint-free cloth to do so.