2011 Mercedes CL-Class Owner's Manual - Page 430

428 Battery Charging the battery G Warning Never charge a battery while still installed in the vehicle unless the accessory battery charge unit approved by Mercedes-Benz is being used. Gases may escape during charging and cause explosions that may result in paint damage, corrosion or personal injury. An accessory battery charge unit specially adapted for Mercedes-Benz vehicles and tested and approved by Mercedes-Benz is available. It permits the charging of the battery in its installed position. Contact an authorized Mercedes-Benz Center for information and availability. Charge the battery in accordance with the separate instructions for the accessory battery charger. X as when connecting the donor battery in the jump-starting procedure (Y page 429). Read the battery charger's operating instructions before charging the battery. Roadside Assistance G Warning There is a risk of acid burns during the charging process due to the gases which escape from the battery. Do not lean over the battery during the charging process. G Warning Battery acid is caustic. Avoid contact with the skin, eyes or clothing. ! Only charge the installed battery with a battery charger which has been tested and approved by Mercedes-Benz. These battery chargers allow the battery to be charged while still installed. ! Only use battery chargers with a maximum charging voltage of 14.8 V. ! Only charge the battery using the jumpstarting connection point. The jump-starting connection point is in the engine compartment (Y page 429). X Open the hood (Y page 404). X Connect the battery charger to the positive terminal and earth point in the same order