Mercedes-Benz MY17 c-class Operator's Manual page 309

Remove the SmartKey if you park the vehicle
and do not require any electrical consumers.
The vehicle will then use very little energy, thus
conserving battery power.
Charging the 12 V battery
Vehicles with a lithium-ion battery:
!
Only use battery chargers with a maximum
charging voltage of 14.4 V.
All other vehicles:
G
WARNING
During charging and jump-starting, explosive
gases can escape from the battery. There is a
risk of an explosion.
Particularly avoid fire, open flames, creating
sparks and smoking. Ensure there is sufficient
ventilation while charging and jump-starting.
Do not lean over a battery.
G
WARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with skin, eyes or clothing. Do
not inhale any battery gases. Do not lean over
the battery. Keep children away from batter-
ies. Wash away battery acid immediately with
plenty of clean water and seek medical atten-
tion.
G
WARNING
A discharged battery can freeze at tempera-
tures below freezing point. When jump-start-
ing the vehicle or charging the battery, gases
can escape from the battery. There is a risk of
an explosion.
Allow the frozen battery to thaw out before
charging it or jump-starting.
!
Only use battery chargers with a maximum
charging voltage of 14.8 V.
All vehicles:
!
Only charge the battery using the jump-
starting connection point.
The jump-starting connection point is in the
engine compartment ( page 308).
Y
Battery (vehicle)
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 battery in the
jump-starting procedure (
Keep away from fire and open flames. Do not
lean over a battery. Never charge the battery if it
is still installed in the vehicle, unless you use a
battery charger which has been tested and
approved by Mercedes-Benz. A battery charger
unit specially adapted for Mercedes-Benz vehi-
cles and tested and approved by Mercedes-
Benz is available as an accessory. It permits the
charging of the battery in its installed position.
Contact an authorized Mercedes-Benz Center
for further information and availability. Read the
battery charger's operating instructions before
charging the battery.
All vehicles except vehicles with a lithium-
ion battery: if the indicator/warning lamps in
the instrument cluster do not light up at low
temperatures, it is very 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 characteristics can
be impaired, particularly at low temperatures.
Have the thawed-out battery checked at a quali-
fied specialist workshop.
Vehicles with a lithium-ion battery: at low
temperatures, do not charge a battery which has
been removed using a battery charger. Allow the
battery to warm up gently first, if necessary.
Otherwise, the service life can be shortened and
the starting characteristics impaired, especially
at low temperatures.
307
page 308).
Y
Z