2012 MERCEDES-BENZ S-Class hood open

! Like other batteries, the vehicle battery
may discharge over time if you do not use
the vehicle. In this case have the battery
checked at a qualified specialist workshop,
such as an authorized Mercedes-Benz
Center. You can also charge the battery
with a charger recommended by Mercedes-
Benz. Contact an authorized Mercedes-
Benz Center for more information.
The battery and the cover of the positive
terminal clamp must be installed securely
during operation.
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.
Mercedes-Benz recommends that you do not
carry out work on batteries yourself, e.g.
removing or charging. Always have this work
performed at a qualified specialist workshop,
e.g. an authorized Mercedes-Benz Center.
Charging the battery
GWARNING
Never charge a battery still installed in the
vehicle unless a battery charger unit approved
by Mercedes-Benz is being used. Gases may
escape during charging and cause explosions
that may result in paint damage, corrosion or
personal injury.
A battery charger unit specially adapted for
Mercedes-Benz vehicles 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.
Charge the battery in accordance with the
separate instructions for the battery charger.
GWARNING
There is a risk of acid burns during the
charging process due to the gases which
escape from the battery. Do not lean over the
battery during the charging process.GWARNING
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. These battery
chargers allow the battery to be charged
while still installed.
! 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 481).
XOpen the hood ( Y page 456).XConnect 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 481).XRead the battery charger's operating
instructions before charging the battery.480BatteryBreakdown assistance

XMake sure that the two vehicles do not touch.XSecure the vehicle by applying the electric parking brake.XShift the transmission to position P.XSwitch off all electrical consumers (e.g. radio, blower, etc.).XOpen the hood ( Y page 456).
Position number A identifies the charged battery of the other vehicle or an equivalent jump-
starting device.
XRemove the cover from positive terminal :.XConnect positive terminal : on your vehicle to positive terminal ; of donor battery A
using the jumper cable, beginning with your own battery.XStart the engine of the donor vehicle and run it at idling speed.XConnect negative terminal = of donor battery A to earth point ? of your vehicle using
the jumper cable, connecting the jumper cable to donor battery A first.XStart the engine.XAllow the engine to run for a few minutes before disconnecting the jumper cable.XFirst, remove the jumper cable from earth point ? and negative terminal =, then from
positive terminal : and positive terminal ;, each time disconnecting from the battery on
your own vehicle first.XHave the battery checked at a qualified specialist workshop, e.g. an authorized Mercedes-
Benz Center. The jump-starting procedure is not a standard operating state; therefore, have
the battery checked.482Jump-startingBreakdown assistance

Fuse box in the engine compartment
Fuse box on the left in the direction of
travelXOpen the hood ( Y page 456).XRemove any existing moisture from the
fuse box using a dry cloth.XAMG vehicles: remove the control unit
above the fuse box.X To open: undo screws : with an Allen
key.XRemove bracket =.XRemove cover ;.XTo close: check whether the rubber seal is
lying correctly in cover ;.XPut cover ; back in position.XReplace bracket =.XTighten screws : using an Allen key.
!
The cover must be seated properly,
otherwise moisture or dirt could impair the
function of the fuses.
XClose the hood ( Y page 457).
Fuse box on the right in the direction of
travel
XOpen the hood ( Y page 456).XRemove any existing moisture from the
fuse box using a dry cloth.XTo open: open clamps ;.XRemove cover ; upwards.XTo close: check whether the rubber seal is
lying correctly in cover ;.XPut cover ; back in position.XFold down cover : and close clamps ;.
!
The cover must be seated properly,
otherwise moisture or dirt could impair the
function of the fuses.
XClose the hood ( Y page 457).
Engine emergency off
If the engine cannot be switched off as
described, observe the following procedure:
XTake the fuse allocation chart out of the
vehicle document wallet.XSearch for “Emergency engine shutdown”
in the fuse allocation chart.XRemove the fuses listed under "Emergency
engine shutdown".Fuses487Breakdown assistanceZ