2012 MERCEDES-BENZ B-CLASS child lock

R
If ABS malfunctions, the wheels can lock
during braking. This limits the steerability
of the vehicle
when braking and the braking
distance may increase. There is a risk of
accident.
R If ESP ®
malfunctions, the vehicle will not be
stabilized if it starts to skid or a wheel starts
to spin. There is a risk of accident.
You should therefore have all work involving
the battery carried out at a qualified specialist
workshop. G
WARNING
Electrostatic build-up can lead to the creation
of sparks, which could ignite the highly
explosive gases of

a battery. There is a risk of
an explosion.
Before handling the battery, touch the vehicle
body to remove any existing electrostatic
build-up.
The highly flammable gas mixture forms when
charging the battery as well as when jump-
starting.
Always make sure that neither you nor the
battery is electrostatically charged. There is
a build-up of electrostatic charge, e.g.:
R by wearing clothing made from synthetic
fibers
R due to friction between clothing and seats
R if you push or pull the battery across the
carpet or other synthetic materials
R if you wipe the battery with a cloth. 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 jumper cables.
R Never connect or disconnect the battery
terminals while the engine is running. G
WARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with

the skin, eyes or clothing.
Do not inhale any battery gases. Do not lean
over the battery. Keep children away from
batteries. Wash battery acid immediately with
water and seek medical attention. H
Environmental note Batteries contain dangerous
substances. It is against the
law to dispose of them with
the household rubbish. They
must be
collected

separately
and recycled to protect the
environment. Dispose of batteries in an
environmentally friendly
manner. Take discharged
batteries to a qualified
specialist workshop or a
special collection point for
used batteries.
! Have the battery checked regularly at a
qualified specialist workshop.
Observe the service intervals in the
Maintenance Booklet or

contact a qualified
specialist workshop for more information.
! You should have all work involving the
battery carried out at a qualified specialist
workshop. In the exceptional case that it is 286
Battery (vehicle)
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necessary for you to disconnect the battery
yourself, make sure that:
R
you switch off
the engine and remove the
SmartKey. Check that 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.
Otherwise, the vehicle's electronic
system may be damaged.
R on vehicles with automatic transmission,
the transmission is locked in position P
after disconnecting the battery. The
vehicle 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 installed securely
during operation.
Comply with safety precautions and take
protective measures when handling
batteries. WARNING
Fire, open flames and smoking are
prohibited when handling the
battery. Avoid creating sparks.
Battery acid is caustic. Avoid
contact with the skin, eyes or
clothing.
Wear suitable protective clothing,
in particular gloves, an apron and
a face mask.
Immediately rinse acid splashes
off with clean water. Consult a
doctor if necessary.
Wear eye protection. Keep children away.
Observe this Operator's Manual.
For safety reasons, Mercedes-Benz
recommends that you only use batteries
which have been tested and approved for
your vehicle by Mercedes-Benz. These
batteries provide increased impact
protection to prevent

vehicle occupants from
suffering acid burns should the battery be
damaged in the event of an accident.
In order for the battery to achieve the
maximum 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 this case, have the battery
disconnected at a qualified specialist
workshop. You can also charge the battery
with a charger recommended by Mercedes-
Benz. Contact a qualified specialist workshop
for further information.
Have the battery charge level checked more
frequently 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 for a long period of time.
Only replace a battery with a battery that has
been recommended by Mercedes-Benz.
i 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. Battery (vehicle)
287
Breakdown assistance Z
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i
If the power supply has been interrupted,
e.g. if you reconnect the battery, you will
have to:
R set the clock (audio system/COMAND,
see the
separate operating instructions).
R reset the function for folding the exterior
mirrors in/out automatically, by folding
the mirrors out once ( Y page 93).Charging the 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, 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

the skin, eyes or clothing.
Do not inhale any battery gases. Do not lean
over the battery. Keep children away from
batteries. Wash battery acid immediately with
water and seek medical attention. 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.
! Only use battery chargers with a
maximum charging voltage of 14.8 V.
! Only charge the battery using the jump-
starting connection point.
The jump-starting connection point is in the
engine compartment (Y

page 289). X
Open the hood (Y page 266).
X Connect the battery charger to the positive
terminal and ground point in the same
order as when connecting the donor
battery in the jump-starting procedure
(Y page 289).
If, at low temperatures, the indicator lamps/
warning lamps in the instrument cluster do
not light up, it is highly 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
thawed-out battery may be shorter. The
starting characteristics can be impaired,
particularly at low temperatures. Have the
thawed-out battery checked at a qualified
specialist workshop.
Only charge the installed battery with a
battery charger which has been tested and
approved by Mercedes-Benz. An accessory
battery charge unit specially adapted 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
information and availability.

Read the battery
charger's operating instructions before
charging the battery. 288
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