2011 Mercedes R-Class Owner's Manual - Page 313

Jump-starting Jump-starting G Warning 311 Failure to follow these directions will cause damage to the electronic components, and can lead to a battery explosion and severe injury or death. Never lean over batteries while connecting or jump starting. You might get injured. Battery fluid contains sulfuric acid. Do not allow this fluid to come in contact with eyes, skin or clothing. In case it does, immediately flush affected area with water, and seek medical help if necessary. A battery will also produce hydrogen gas, which is flammable and explosive. Keep flames or sparks away from battery, avoid improper connection of jumper cables, smoking, etc. Attempting to jump start a frozen battery can result in it exploding, causing personal injury. Read all instructions before proceeding. ! Avoid repeated and lengthy starting attempts. Otherwise, non-combusted fuel may damage the catalytic converter41 and create a risk of fire. Do not use a rapid-charging device to start the engine. Make sure the jumper cables are not damaged. Make sure the jumper cables are not touching any other metal objects when they are connected to the battery. If your vehicle's battery is discharged, the engine can be jump-started from another vehicle or from a second battery using jumper cables. Observe the following points: X The battery is not accessible in all vehicles. If the other vehicle's battery is not accessible, jump-start the vehicle using a second battery or a jump-starting device. X Only jump-start the vehicle when the engine is cold and the catalytic converter system has cooled down42 . X Do not start the engine if the battery is frozen. Let the battery thaw first. X Jump-starting may only be performed from batteries with a nominal voltage of 12 V. If you jump-start using a battery with higher voltage, it may damage the electrical systems of the vehicle. X Only use jumper cables which have a sufficient cross-section and insulated terminal clamps. X Make sure that the jumper cables cannot come into contact with parts, such as the pulley or the fan. These parts move when the engine is started and while it is running. X If the battery is fully discharged, leave the battery that is being used to jump-start connected for a few minutes before attempting to start. This charges the battery a little. i Jumper cables and further information about jump-starting can be obtained from any authorized Mercedes-Benz Center. X Make sure that the two vehicles do not touch. X Apply the parking brake firmly. 41 Only 42 Only vehicles with a gasoline engine. vehicles with a gasoline engine. Z Roadside Assistance