Mercedes-Benz S-Class Saloon W223 2021 Owner's Manual page 386

384 Breakdown assistance
the jump lead. Start with the donor vehicle
first.
Start the engine of your own vehicle.
#
Let the engines run for several minutes.
#
Before disconnecting the jump leads, switch
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on an electrical consumer in your own vehicle,
e.g. the rear window heater or the lighting.
When starting assistance has finished:
First, remove the jump lead from the earth
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point of your own vehicle and the negative ter-
minal of the donor battery, then remove the
jump lead from the positive contacts of both
vehicles. Always start with your own vehicle
first.
Close protective cover 2 of positive contact
#
3 and close cover 1.
Further information can be obtained at a qualified
specialist workshop.
Charging the 12 V battery
Connect the positive contacts of the vehicle
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and the charger with the charging cable. Start
with the vehicle first.
Connect the negative contact of the charger
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and earth point 4 on the vehicle with the
charging cable. Start with the charger first.
Start the charging process.
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When the charging process is complete:
Remove the charging cable from earth point
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4 on the vehicle and the negative contact of
the charger first and then from the positive
contacts on the vehicle and charger. Always
start with the vehicle first.
Close protective cover 2 of positive contact
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3 and close cover 1.
Replacing the 12 V battery
Observe the notes on the 12 V battery
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( page 379).
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P223 0288 02
Mercedes-Benz recommends that you have the
12 V battery replaced at a qualified specialist
workshop, e.g. at a Mercedes-Benz Service
Centre.
Observe the following notes if you want to replace
the battery yourself:
Always replace a faulty battery with a battery
R
which meets the specific vehicle require-
ments.
The vehicle is equipped with an AGM technol-
ogy battery (Absorbent Glass Mat) or a lith-
ium-ion battery. Full vehicle functionality is
only guaranteed with an AGM battery or lith-
ium-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
R
hoses, elbow fittings or terminal covers from
the battery being replaced.
Make sure that the vent hose is always con-
R
nected to the original opening on the side of
the battery.
Fit any existing or supplied cell caps.