Mercedes-Benz 2015 M-Class Operator's Manual page 392

Battery (vehicle)
390
! Only use battery chargers with a maxi-
mum charging voltage of 14.8 V.
! Only charge the battery using the jump-
starting connection point.
If, at low temperatures, the indicator lamps/
warning lamps in the instrument cluster do
not light up, it is highly likely that the dis-
charged battery has frozen. In this case you
may neither jump-start the vehicle nor charge
the battery. The service life of a thawed-out
battery may be shorter. The starting charac-
teristics can be impaired, particularly at low
temperatures. Have the thawed-out battery
checked at a qualified specialist workshop.
Never charge a battery still installed in the
vehicle unless a battery charger unit
approved by Mercedes-Benz is being used. An
accessory battery charge unit specially adap-
ted 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 further informa-
tion and availability. Charge the battery in
accordance with the separate instructions for
the battery charger.
The jump-starting connection point is in the
engine compartment (
Read the battery charger's operating instruc-
tions before charging the battery.
Open the hood.
X
Connect the battery charger to the positive
X
terminal and ground point in the same
order as when connecting the donor bat-
tery in the jump-starting procedure
( page 391).
Y
page 391).
Y