Mercedes-Benz C-Class (W205) 2015 - 2021 Owners Manual: Starting assistance and charging the 12 V battery

Requirements:

• The vehicle is secured with the electric parking brake.
• Automatic transmission: The transmission is in position P.
• The ignition and all electrical consumers are switched off.
• The hood is open.

• Fold cover 1 up in the direction of the arrow.

• Slide cover 2 of positive clamp 3 on the jump-starting connection point in the direction of the arrow.
• Connect positive clamp 3 on your vehicle to the positive pole of the donor battery using the jumper cable/charging cable. Always begin with positive clamp 3 on your own vehicle first.
• During starting assistance: start the engine of the donor vehicle and run at idle speed.
• Connect the negative pole of the donor battery and ground point 4 of your own vehicle by using the jumper cable/charging cable.

  Begin with the donor battery first.

• During starting assistance: start the engine of your own vehicle.
• During the charging process: start the charging process.
• During starting assistance: let the engines run for several minutes.
• During starting assistance: before disconnecting the jumper cable, switch on an electrical consumer in your own vehicle, e.g. the rear window heater or lighting.

When the starting assistance/charging process is complete:

• First, remove the jumper cable/charging cable from ground point 4 and negative pole of the donor battery, then from positive clamp 3 and positive pole of the donor battery. Begin each time with the contacts on your own vehicle first.
• After removing the jumper cable/charging cable, close cover 2 of positive clamp 3.
• Close cover 1.

Further information can be obtained at a qualified specialist workshop.

Replacing the 12 V battery

• Observe the notes on the 12 V battery

Mercedes-Benz recommends that you have the 12 V battery replaced at a qualified specialist workshop, e.g. at an authorized Mercedes-Benz Center.

Observe the following notes if you want to replace the battery yourself:

• Always replace a faulty battery with a battery which meets the specific vehicle requirements.

  The vehicle is equipped with an AGM technology battery (Absorbent Glass Mat) or a lithium- ion battery. Full vehicle functionality is only guaranteed with an AGM battery or lithium- ion battery. For safety reasons, Mercedes-Benz recommends that you only use batteries which have been tested and approved for your vehicle by Mercedes-Benz.

• Carry over detachable parts, such as vent hoses, elbow fitting or terminal covers from the battery being replaced.
• Make sure that the vent hose is always connected to the original opening on the side of the battery.

  Install any existing or supplied cell caps.

  Otherwise, gases or battery acid could escape.

• Make sure that detachable parts are reconnected in the same way.