Charging the 12 V battery
G
WARNING
During charging and jump-starting, explosive
gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, naked 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 the skin, eyes or clothing.
Do not breathe in any battery gases. Do not
lean over the battery. Keep the batteries out
of the reach of children. Immediately rinse off
battery acid thoroughly with plenty of clean
water and seek medical attention at once. 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 maxi-
mum charging voltage of 14.8 V.
! Only charge the battery using the jump-
start connection point.
The jump-starting connection point is in the
engine compartment (Y page 422).
X Open the bonnet.
X Connect the battery charger to the positive
terminal and earth point in the same order
as when connecting the donor battery in
the jump-starting procedure (Y page 422).
Never charge the battery if it is still fitted to
the vehicle, unless you use a battery charger which has been tested and approved by
Mercedes-Benz. A battery charger unit spe-
cially adapted for Mercedes-Benz vehicles and tested and approved by Mercedes-Benz
is available as an accessory. This device per-
mits charging of the battery in position. Con-
tact a Mercedes-Benz Service Centre for
information and availability. Read the battery charger's operating instructions before
charging the battery.
If the indicator/warning lamps do not light up
at low temperatures, it is very likely that the
discharged battery has frozen. In this case
you may neither jump-start the vehicle nor
charge the battery. The service life of a bat-
tery that has been thawed may be reduced.
The starting characteristics may be impaired, especially at low temperatures. Have the
thawed battery checked at a qualified spe-
cialist workshop.
Hybrid vehicles: if the battery charge is suf-
ficient, the high-voltage battery can also sup-
ply the 12 V battery with energy. This only
happens if the battery charge of the 12 V bat-
tery requires this, e.g. after using electrical
consumers for an extended period with the
engine switched off. As the on-board voltage
is continuously monitored this can also be
performed when the engine is switched off.
The battery charge of the 12 V battery and the
on-board voltage are thereby kept stable for
longer. Charging the high-voltage battery
when stationary
Only hybrid vehicles are equipped with a high-
voltage battery. G
WARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. Inhaling
these exhaust gases leads to poisoning. There is a risk of fatal injury. Therefore never leave
the engine running in enclosed spaces with-
out sufficient ventilation.
! Only charge the high-voltage battery in
the "Charging when stationary" mode. Do
not connect a battery charger to the high- 420
Battery (vehicle)Breakdown assistance
Jump-starting
For the jump-starting procedure, use only the jump-starting connection point, consisting of a positive terminal and an earth point, in the engine compartment. G
WARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with the skin, eyes or clothing. Do not breathe in any battery gases. Do not lean over the battery. Keep the batteries out of the reach of children. Immediately rinse off battery acid
thoroughly with plenty of clean water and seek medical attention at once. G
WARNING
During charging and jump-starting, explosive gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, naked flames, creating sparks and smoking. Ensure there is sufficient
ventilation while charging and jump-starting. Do not lean over a battery. G
WARNING
During the charging process, a battery produces hydrogen gas. If a short circuit occurs or sparks
are created, the hydrogen gas can ignite. There is a risk of an explosion.
R Make sure that the positive terminal of a connected battery does not come into contact with
vehicle parts.
R Never place metal objects or tools on a battery.
R It is important that you observe the described order of the battery terminals when connecting
and disconnecting a battery.
R When jump-starting, make sure that the battery poles with identical polarity are connected.
R It is particularly important to observe the described order when connecting and disconnecting
the jump leads.
R Never connect or disconnect the battery terminals while the engine is running. G
WARNING
A discharged battery can freeze at temperatures below freezing point. When jump-starting 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.
! Vehicles with a petrol engine:
avoid repeated and lengthy starting attempts. Otherwise,
the non-combusted fuel may damage the catalytic converter.
If the indicator/warning lamps do not light up at low temperatures, it is very likely that the
discharged battery has frozen. In this case you may neither jump-start the vehicle nor charge
the battery. The service life of a battery that has been thawed may be reduced. The starting
characteristics may be impaired, especially at low temperatures. Have the thawed battery
checked at a qualified specialist workshop. 422
Jump-startingBreakdown assistance
Do not use a rapid charging device to start the vehicle. If your vehicle's battery is discharged,
the engine can be jump-started from another vehicle or from a second battery using jump
leads. Observe the following points:
R The battery is not accessible in all vehicles. If the other vehicle's battery is not accessible,
jump-start the vehicle using a second battery or a jump-starting device.
R Vehicles with a petrol engine: only jump-start the vehicle when the engine and exhaust
system are cold.
R Do not start the engine if the battery is frozen. Let the battery thaw first.
R Jump-starting may only be performed using batteries with a nominal voltage of 12 V.
R Only use jump leads that have a sufficient cross-section and insulated terminal clamps.
R If the battery is fully discharged, leave the battery that is being used to jump-start connected
for a few minutes before attempting to start. This charges the empty battery a little.
R Make sure that the two vehicles do not touch.
Make sure that:
R The jump leads are not damaged.
R Non-insulated parts of the terminal clamps do not come into contact with other metal parts
while the jump leads are connected to the battery.
R The jump leads cannot come into contact with parts which can move when the engine is
running, such as the V-belt pulley or the fan.
X Secure the vehicle by applying the electric parking brake.
X Automatic transmission: shift the transmission to position P.
X Manual transmission: depress the clutch pedal fully and shift to neutral.
X Make sure the ignition is switched off (Y page 185). All indicator lamps in the instrument
cluster must be off. When using the key, turn the key to position 0in the ignition lock and
remove it (Y page 185).
X Switch off all electrical consumers, e.g. rear window heating, lighting etc.
X Open the bonnet. Jump-starting
423Breakdown assistance Z
!
When COLLISION PREVENTION ASSIST
PLUS, DISTRONIC PLUS or the HOLD func- tion is activated, the vehicle brakes auto-
matically in certain situations. To avoid
damage to the vehicle, deactivate these
systems in the following or similar situa-
tions:
R when towing away
R in a car wash
! Make sure that the electric parking brake
is released. If the electric parking brake is
faulty, visit a qualified specialist workshop.
! Only secure the tow cable or tow bar to
the towing eyes or, if available, to the trailer
tow hitch. You could otherwise damage the
vehicle.
! Observe the following points when towing
with a tow rope:
R secure the tow rope on the same side on
both vehicles.
R make sure that the tow rope is not longer
than legally permitted. Mark the tow rope
in the middle, e.g. with a white cloth
(30 x 30 cm). This makes other road
users aware that a vehicle is being
towed.
R only secure the tow rope to the towing
eye.
R observe the brake lamps of the towing
vehicle while driving. Always maintain a
distance so that the tow rope does not
sag.
R do not use steel cables or chains to tow
your vehicle. You could otherwise dam-
age the vehicle.
! Do not use the towing eyes for recovery
purposes as this could damage the vehicle.
If in doubt, recover the vehicle with a crane.
! Pull away smoothly when towing away or
tow-starting a vehicle. If the tractive power
is too high, the vehicles could be damaged.
! Shift the automatic transmission to
Nand
do not open the driver's or front passeng- er's door during towing. The automatic
transmission may otherwise shift to posi-
tion
P, which could damage the transmis-
sion.
! You may tow the vehicle for a maximum of
50km. A towing speed of 50 km/h must not
be exceeded.
For towing distances over 50 km, the entire vehicle must be lifted up and transported.
! If you tow or tow-start another vehicle, its
weight must not exceed the maximum per- missible gross vehicle weight of your vehi-
cle.
Details on the permissible gross vehicle
weight of your vehicle can be found on the
vehicle identification plate (Y page 470).
Observe the legal requirements for the rele-
vant countries when towing.
It is better to have the vehicle transported
than to have it towed.
If the vehicle has suffered transmission dam-
age, have it transported on a transporter or
trailer.
Vehicles with automatic transmission:
when towing a vehicle, the automatic trans-
mission must be in position N. If the auto-
matic transmission cannot be shifted to posi- tion N, have the vehicle transported on a
transporter or trailer.
The battery must be connected and charged.
Otherwise, you:
R cannot turn the key in the ignition lock to
position 2
R cannot release the electric parking brake
R cannot shift the transmission to position N
on vehicles with automatic transmission
Deactivate the automatic locking feature
before the vehicle is towed (Y page 98). You
could otherwise be locked out when pushing
or towing the vehicle.
Deactivate tow-away protection (Y page 88)
before the vehicle is towed.
Hybrid vehicles: Towing away and tow-starting
425Breakdown assistance Z
Towing the vehicle with both axles on
the ground
Vehicles with automatic transmission: the
automatic transmission automatically shifts
to position Pwhen you open the driver's or
front-passenger door or when you remove the
key from the ignition lock. In order to ensure that the automatic transmission stays in posi-
tion Nwhen towing the vehicle, you must
observe the following points:
X Make sure that the vehicle is stationary.
X Turn the key to position 2in the ignition
lock.
X Depress and hold the brake pedal.
X Shift the automatic transmission to posi-
tion N.
Vehicles with manual transmission: X Turn the key to position 2in the ignition
lock.
X Depress and hold the brake pedal.
X Depress the clutch pedal fully and shift to
neutral.
Vehicles with manual or automatic trans-
mission:
X Leave the key in position 2in the ignition
lock.
X Release the brake pedal.
X Release the electric parking brake.
X Switch on the hazard warning lamps
(Y page 137).
In order to signal a change of direction when towing the vehicle with the hazard warning
lamps switched on, use the combination
switch as usual. In this case, only the turn
signals for the desired direction flash. When
you reset the combination switch, the hazard
warning lamps start flashing again. Transporting the vehicle
Hybrid vehicles: transportation of the vehi-
cle should only be carried out by professional
recovery companies. !
You may only secure the vehicle by the
wheels, not by parts of the vehicle such as
axle or steering components. Otherwise,
the vehicle could be damaged.
The towing eyes or trailer tow hitch can be
used to pull the vehicle onto a trailer or trans-
porter if you wish to transport it.
X Vehicles with manual transmission:
depress the clutch pedal fully and shift to
neutral.
X Vehicles with automatic transmission:
turn the key to position 2in the ignition
lock.
X Shift the automatic transmission to posi-
tion N.
As soon as the vehicle is loaded:
X Prevent the vehicle from rolling away by
applying the electric parking brake.
X Vehicles with manual transmission:
depress the clutch pedal fully and engage
first or reverse gear.
X Vehicles with automatic transmission:
shift the automatic transmission to posi-
tion P.
X Turn the key to position 0in the ignition
lock and remove it.
X Secure the vehicle. Notes for 4MATIC vehicles
! Vehicles with 4MATIC must not be towed
with the front or rear axle raised; otherwise,
the transmission may be damaged.
Vehicles with 4MATIC may either be towed
away with both axles on the ground or be loa- ded up and transported.
If the vehicle has transmission damage or
damage to the front or rear axle, have it trans-
ported on a transporter or trailer.
In the event of damage to the electrical
system: if the battery is defective, the auto-
matic transmission will be locked in position
P. To shift the automatic transmission to posi- Towing away and tow-starting
427Breakdown assistance Z