Mercedes-Benz V-Class 2021 Owner's Manual page 251

248 Breakdown assistance
donor battery, and then to earth contact
of your own vehicle.
Start the engine of the donor vehicle and run
#
it at idling speed.
Insert the key into the ignition lock, start the
#
engine and let it run for several minutes.
Before disconnecting the jump leads, switch
#
on an electrical consumer in your own vehi‐
cle, e.g. the rear window heater or the light‐
ing.
Disconnect the negative terminal clamp of
#
the jump lead from earth contact
then from negative terminal
battery.
Disconnect the positive terminal clamp of the
#
jump lead from positive terminal
jump-start connection point, and then from
positive terminal 3
Contact protection cover
returned forwards to its original position by
the spring force and the jump-start connec‐
tion point is closed.
Position the cover on positive terminal
#
the donor battery.
Have the battery checked at a qualified spe‐
#
cialist workshop.
Charging the 12 V battery
* NOTE Damage to the electronics caused
by non-approved charging devices
Charging a fitted battery with a battery
charger which has not been approved by
Mercedes-Benz can damage the on-board
electronics.
Only use a battery charger which has
#
been approved by Mercedes-Benz and
which permits charging the battery
when it is fitted in the vehicle.
Only charge the battery using the jump-
#
start connection point.
A battery charger specially adapted for
Mercedes-Benz vehicles and tested and approved
for Mercedes-Benz is available as an accessory.
Further information is available from any
Mercedes-Benz Service Centre. Read the operat‐
ing instructions for your charger before charging
the battery.
Recharge the battery more frequently if you use
the vehicle mainly for short trips and/or drive at
low outside temperatures.
4
4 and
2 of the donor
5 on the
of the donor battery.
1 is automatically
3 of
Connect the battery charger to the positive
#
terminal and earth contact in the same order
as when connecting the donor battery in the
jump-starting procedure.
%
If a battery is not fitted and not in service,
you should charge it every three months. This
helps to counteract self-discharging and pre‐
vent damage to the battery.
12 V battery care
* NOTE Battery discharge due to leakage
currents
Dirty battery terminal clamps and battery sur‐
faces cause leakage currents. This can lead
to the battery discharging.
Keep the battery terminals and battery
#
surfaces clean and dry.
* NOTE Damage to the battery housing
due to improper cleaning
If you use cleaning agents containing fuel,
these can damage the battery housing.
Do not use cleaning agents containing
#
fuel.
* NOTE Damage to the battery due to self-
discharge
If dirt gets into the battery cell, the self-dis‐
charge of the battery is increased and the
battery can be damaged.
Only clean the battery with the cell caps
#
screwed in.
Observe the following points on battery care:
Regularly check the battery terminals and the
#
fastening of the negative cable to the chassis
to ensure that they are firmly seated.
Lightly grease the undersides of the battery
#
terminal clamps with acid-resistant grease.
Only clean the battery housing with commer‐
#
cially available cleaning agents.