2011 MERCEDES-BENZ B-CLASS HATCHBACK key battery

Battery acid is caustic.
Avoid contact with the skin,
eyes or clothing.
Wea
rsuitable protective
clothing, in particular
gloves, an apro nand a face
mask.
Immediately rinse acid
splashes off with clean
water. Consult a doctor if
necessary. Wear eye protection.
Keep children away.
Observe this Owner's Man-
ual.
G
WARNING
For safety reasons, Mercedes-Benz recom-
mends tha tyou only use batteries which have
been tested and approved for your vehicle by
Mercedes-Benz. These batteries provide
increased impact protection to prevent vehi-
cle occupants from suffering acid burns
should the battery be damaged in the event
of an accident.
To prevent acid burns, observe the following
safety notes when handling batteries:
R do not lean over the battery.
R do not place any metal objects on a battery.
Otherwise, you could cause a short circuit
and the battery's gas mixture could ignite.
R make sure that you do not create an elec-
trostatic charge, e.g. by wearing synthetic
clothing or as a result of friction on fabrics.
Therefore, you should not pull or slide the
battery over carpets or other synthetic
materials. R
never touch the battery first. To discharge
a possible electrostatic charge, step out of
the vehicle first and touch the bodywork.
R do not wipe the battery using a cloth. The
battery may explode as a result of electro-
static charge or due to flying sparks. H
Environmental note Batteries contain pollutants.
It is illegal to dispose of them
with the household rubbish.
They must be collected sep-
arately and disposed of in an
environmentally responsible
recycling system.
Dispose of batteries in an
environmentally responsible
manner
.Take discharged
batteries to a qualified spe-
cialis tworkshop or to a col-
lection point for used batter-
ies.
! Have the battery checked regularly at a
qualified specialist workshop.
Observe the service intervals in the Service
Booklet or contact a qualified specialist
workshop for more information.
! You should have all work involving the
battery carried out at aqualified specialist
workshop. In the exceptional case that it is
necessary for you to disconnect the battery
yourself, make sure that:
R you switch off the engine and remove the
key. On vehicles with KEYLESS-GO,
ensure that the ignition is switched off.
Chec kthat all the indicator lamps in the
instrument cluster are off. Otherwise,
electronic components, such as the
alternator, may be damaged.
R you first remove the negative terminal
clamp and then the positive terminal
clamp. Never swap the terminal clamps. Battery
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Otherwise, the vehicle's electronic sys-
tem may be damaged.
R in vehicles with automatic transmission,
the transmission is locked in position P
after disconnecting the battery. The vehi-
cle is secured against rolling away. You
can then no longer move the vehicle.
The battery and the cover of the positive
terminal clamp must be fitted securely dur-
ing operation.
In order for the battery to achieve the maxi-
mum possible service life, it must always be
sufficiently charged.
Like other batteries, the vehicle battery may
discharge over time if you do not use the
vehicle. In such cases, have the battery dis-
connected at a qualified specialist workshop.
You can also charge the battery with a
charger recommended by Mercedes-Benz.
For more information, please contact a quali-
fied specialist workshop.
Have the battery charge checked more fre-
quently if you use the vehicle mainly for short
trips or if you leave it standing idle for a
lengthy period. Consult a qualified specialist
workshop if you wish to leave your vehicle
parked up for a long period of time.
i When you park the vehicle, remove the
key if you do not require any electrical con-
sumers. The vehicle will then use very little
energy, thus conserving battery power.
i If the power supply has been interrupted,
e.g. if the battery was discharged, you must
carry out the following tasks:
R set the clock (audio system/COMAND
Online, see the separate operating
instructions).
R reset the function for automatically fold-
ing the exterior mirrors in/out by folding
the mirrors out once (Y page 92). Charging the battery
G
WARNING
Only charge the battery in a well-ventilated
area. As the battery is being charged, gases
can escape and generate minor explosions.
This could injure you and other persons or
cause damage to the paintwork or acid cor-
rosion on the vehicle.
You can obtain information on battery charg-
ers which allow the battery to be charged
while still installed from a qualified specialist
workshop. G
WARNING
There is a risk of acid burns during the charg-
ing process due to the gases which escape
from the battery. Do not lean over the battery
during the charging process. G
WARNING
Battery acid is caustic. Avoid contact with the
skin, eyes or clothing.
! Only charge the installed battery with a
battery charger which has been tested and
approved by Mercedes-Benz.T hese battery
chargers allow the battery to be charged
while still installed in the vehicle.
! 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 283).
Read the battery charger's operating instruc-
tions before charging the battery.
X Open the bonnet (Y page 262).
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 283). 282
BatteryBreakdown assistance

Jump-starting
G
WARNING
There is a risk of acid burns when jump-starting a vehicle due to the gases which escape from
the battery. Do not lean over the battery while the engine is being jump-started. G
WARNING
Gases escaping from the battery during jump-starting may cause minor explosions. Avoid cre-
ating sparks. Keep naked flames away from the battery, and do not smoke.
Comply with safety precautions when handling batteries. You will find these under "Battery (vehi-
cle)" in the index. G
WARNING
Non-combusted fuel can collect in the exhaust system and ignite. There is a risk of fire. Avoid
repeated and lengthy starting attempts.
! Avoid repeated and lengthy starting attempts. Otherwise, the catalytic converter could be
damaged by the non-combusted fuel.
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 ajump-starting device.
R You may only jump-start the vehicle when the engine and catalyti cconverter 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 from 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.T his 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 bare parts of the terminal clamp 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 such as the V-belt pulley or the fan.
These parts move when the engine is started and while it is running.
X Secure the vehicle by applying the electric parking brake.
X Manual transmission: engage neutral.
X Automatic transmission: shift the transmission to position P.
X Turn the key to position 0in the ignition lock and remove it.
X Switch off all electrical consumers (e.g. radio, blower, etc.).
X Open the bonnet (Y page 262). Jump-starting
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Position number
Bidentifies the charged battery of the other vehicle or an equivalent jump-
starting device.
X Press together cover :of positive clamp ;and slide it back.
X Connec tpositive terminal ;on your vehicle to positive terminal =of donor battery B
using the jump lead, beginning with your own battery.
X Start the engine of the donor vehicle and run it at idling speed.
X Connect negative terminal ?of donor battery Bto earth point Aof your vehicle using
the jump lead, connectingt he jump lead to donor battery Bfirst.
X Start the engine.
X Before disconnecting the jump leads, let the engine run for several minutes.
X Turn the key to position 0in the ignition lock and remove it.
X First, remove the jump leads from earth point Aand negative terminal ?, then from pos-
itive terminal ;and positive terminal =, each time beginning at the contacts on your own
vehicle first.
X Close cover :of positive terminal ;after removing the jump leads.
X Have the battery checked at a qualified specialist workshop.
i Jump-starting is not considered to be a normal operating condition.
i Jump-starting cables and further information regarding jump starting can be obtained at
any qualified specialist workshop. Towing and tow-starting
Important safety notes
G
WARNING
If you tow the vehicle, you must use a rigid
towing bar if: R
the engine is not running.
R there is a brake system malfunction.
R there is a malfunction in the power supply
or the vehicle's electrical system.
The power assistance for the steering and the
brake force booster do not work when the 284
Towing and tow-startingBreakdown assistance

engine is not running. You will need more
force to steer and brake, you may have to
depress the brake pedal with maximum force.
Before towing away, make sure that the steer-
ing can be moved and is not locked.
If you tow or tow-start another vehicle, its
weight must not exceed the maximum per-
missible gross vehicle weight of your vehicle. G
WARNING
The vehicle is braked when the HOLD function
or DISTRONIC PLUS is activated. Therefore,
deactivat eHOLD and DISTRONIC PLUS if the
vehicle is to be towed.
! 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 front
axle or the entire vehicle must be raised
and transported.
! Only secure the tow rope or towing bar to
the towing eyes. The vehicle may otherwise
be damaged.
! Do not use the towing eye for recovery,
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.
! Vehicles with automatic transmission
must not be tow-started. The transmission
may otherwise be damaged.
Observe the legal requirements for the rele-
vant countries when towing and tow-starting.
It is better to have the vehicle transported
than to have it towed.
Vehicles with automatic transmission:
when towing a vehicle, the transmission must
be in position N. The battery must be connected and charged.
Otherwise, you:
R
cannot turn the key in the ignition lock to
position 2
R vehicles with automatic transmission:
cannot shift the transmission to position N
i Deactivate the automatic locking feature
(Y page 203). You could otherwise be
locked out when pushing or towing the
vehicle.
Deactivate tow-away protection
(Y page 69) before the vehicle is towed. Fitting/removing the towing eye
Fitting the towing eye X
Remove the towing eye from the stowage
space.
The towing eye is under the tyre inflation
compressor in the stowage space beneath
the luggage compartment floor
(Y page 275).
X Press the mark on cover :inwards in the
direction of the arrow.
X Take cover :off the opening.
X Screw the towing eye in clockwise to the
stop and tighten it. Towing and tow-starting
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It is important that you observe the safety
instructions when towing away yourv ehicle
(Y page 284). Transporting the vehicle
! Only lash the vehicle down by the wheels
or wheel rims, not by parts of the vehicle
such as axle or steering components. Oth-
erwise, the vehicle could be damaged.
X Vehicles with manual transmission:
shift to neutral.
X Vehicles with automatic transmission:
turn the key to position 2in the ignition
lock.
X Shift the transmission to position N.
As soon as the vehicle is loaded:
X Preven tthe vehicle from rolling away by
applying the electric parking brake.
X Vehicles with manual transmission:
shift to first gear or reverse gear.
X Vehicles with automatic transmission:
shift the transmission to position P.
X Turn the key to position 0in the ignition
lock and remove it.
X Secure the vehicle.
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. Tow-starting (emergency engine
starting)
! Vehicles with automatic transmission
must not be tow-started. Otherwise, you
could damage the automatic transmission.
Before tow-starting the following conditions
must be fulfilled:
R the battery is connected.
R the engine has cooled down.
R the catalytic converters have cooled down. X
Switch on the hazard warning lamps
(Y page 99).
X Fit the towing eye (Y page 285).
X Secure the rigid towing bar or the towing
rope.
X Depress and hold the brake pedal.
X Turn the key to position 2in the ignition
lock.
X Depress the clutch pedal and keep it
depressed.
X Engage neutral.
X Release the brake pedal.
X Tow-start the vehicle.
X Engage second gear.
X Release the clutch pedal slowly without
depressing the accelerator pedal.
The engine is started.
X Depress the clutch pedal and shift to neu-
tral.
X Stop at a suitable place.
X Secure the vehicle by applying the electric
parking brake.
X Remove the rigid towing bar or towing rope.
X Remove the towing eye (Y page 286).
X Switch off the hazard warning lamps.
When tow-starting, it is important that you
observe the safety instructions (Y page 284)
and the legal requirements in each respective
country. Electrical fuses
Important safety notes
G
WARNING
Only use fuses that have been approved for
Mercedes-Ben zvehicles and which have the
correct fuse rating for the systems con-
cerned. Do not attempt to repair or bridge
faulty fuses. Using fuses which have not been
approved or attempting to repair or bridge
faulty fuses could cause the fuse to be over-
loaded and result in a fire. Have the cause Electrical fuses
287Breakdown assistance
Z