battery MERCEDES-BENZ S550 2007 W221 Owner's Guide

635 Practical hints
Batteries
!
The consumer battery located in the trunk is
a valve-r
egulated l
ead a
cid (VRLA) battery, also
referred to as “fleece” battery. Such batteries do
not require topping-up of the electrolyte level.
VRLA batteries therefore do not have cell caps
and the battery cover is non-removable. Do not
attempt to open the consumer battery as other-
wise the battery will be damaged.
Even though VRLA batteries do not require top-
ping-up of the electrolyte level and cannot be
opened to check the electrolyte level, the bat-
tery condition must be checked periodically by
performing a battery conductance test. Refer to
Maintenance Booklet for battery condition test-
ing intervals.
As with any other battery, disconnect the con-
sumer battery if you do not intend to operate
your vehicle for an extended period of time to
prevent battery discharge or connect an acces-
sory battery charge unit expressly approved by
Mercedes-Benz for your vehicle model to main-
tain the battery charge. Contact an authorized
Mercedes-Benz Center for further information.
!
The factory-equipped VRLA battery is
leak-proofed. Only use a battery as replacement
that has the same security features and is of
identical size, voltage, and capacity as the facto-
ry-equipped battery.
The battery, the battery ventilation and the later-
al plug must always be securely installed when
the vehicle is in operation.
Warning!
G
Failure to follow these instructions can re-
sult in severe injury or death.
Never lean over batteries while connecting,
you might get injured.
Battery fluid contains sulfuric acid. Do not
allow this fluid to come in contact with eyes,
skin or clothing. In case it does, immediately
flush affected area with water and seek
medical help if necessary.
A battery will also produce hydrogen gas,
which is flammable and explosive. Keep
flames or sparks away from battery, avoid
improper connection of jumper cables,
smoking, etc.Warning!
G
Do not place metal objects on the battery as
this could result in a short circuit.
Use leak-proof battery only to avoid the risk
of acid burns in the event of an accident.
Take care that you do not become statically
charged, e.g. by wearing synthetic clothing
or rubbing against textiles. For this reason,
you also should not pull or push the battery
over carpets or other synthetic materials.
Never touch the battery first. First touch the
outside body of the vehicle in order to re-
lease any possible electrostatic charges.


636 Practical hintsBatteries
Starter battery (example illustration from
S550)1Negative terminal
2Positive terminal
Disconnecting starter battery
Do not rub the battery with rags or cloths.
The battery could explode if touched due to
electrostatic charge or due to spark forma-
tion.!
Switch off the engine and switch off the ve-
hicle’s internal electrical functions (
page 637)
before you disconnect or remove the battery’s
terminal clamps. You could otherwise destroy
electronic assemblies such as the generator.
Have the battery checked regularly by an autho-
rized Mercedes-Benz Center. Refer to Mainte-
nance Booklet for maintenance intervals or
contact an authorized Mercedes-Benz Center for
further information.
!
Do not connect any consumers directly to
the starter battery. The starter battery will other-
wise be discharged.
i
Only replace a discharged battery with a bat-
tery recommended by Mercedes-Benz. The con-
sumer battery is installed in the trunk in such a
way that it is safeguarded as much as possible
against mechanical destruction in the event of
an accident.
i
Remove SmartKey from starter switch (vehi-
cles with KEYLESS-GO*: Make sure the vehicle’s
on-board electronics have status 0)
(
page 315) when you turn off the engine and
no longer require any electrical consumers. The
vehicle then uses very little power and the con-
sumer battery is spared.
i
If the consumer battery is discharged, you
must use the mechanical key to unlock the vehi-
cle (page 614). Since the vehicle has a sepa-
rate starter battery, however, you can still start
the vehicle.
!
Always disconnect the starter battery in the
order described below. You could otherwise
damage the vehicle’s electronics.
!
Switch off the vehicle’s internal electrical
functions before disconnecting the starter bat-
tery. If the vehicle is stationary for more than one
hour with the SmartKey removed, you do not
need to switch off the vehicle’s internal electrical
functions.


637 Practical hints
Batteries
Switching off vehicle’s internal electri-
cal functions
Shift the automatic transmission toP.

Turn off all electrical consumers.

Turn SmartKey in starter switch to po-
sition 0.

Turn SmartKey in starter switch to po-
sition 1.

Wait for 30 seconds.
The vehicle’s internal electrical func-
tions are switched off.

Turn SmartKey in starter switch to po-
sition 0.Disconnecting starter battery

Open the hood (
page 492).

Use a 10-mm open-end wrench to dis-
connect the battery negative lead.

Remove cover2 (
page 636) from
the positive terminal.

Disconnect the battery positive lead.
Removing starter battery
Pull out the battery ventilation hose
from the battery (depending on battery
arrangement in your vehicle model, the
ventilation hose is located either on the
left or right side of the battery).

Fold bar on starter battery up.

Take out the starter battery.
Charging battery
i
Vehicles with KEYLESS-GO: remove the
KEYLESS-GO button (
page 316) and use the
SmartKey with KEYLESS-GO like a normal
SmartKey.
!
Do not remove the SmartKey!
i
For your convenience, have the starter bat-
tery removed by a Mercedes-Benz Center.
Warning!
G
Never charge a battery while still installed in
the vehicle unless the accessory battery
charge unit approved by Mercedes-Benz is
being used. Gases may escape during charg-
ing and cause explosions that may result in
paint damage, corrosion or personal injury.
An accessory battery charge unit specially
adapted for Mercedes-Benz vehicles and
tested and approved by Mercedes-Benz is
available, permitting the charging of the bat-
tery in its installed position. Contact an au-
thorized Mercedes-Benz Center for
information and availability. Charge battery
in accordance with the separate instruc-
tions for the accessory battery charger.i
Have the batteries charged by a
Mercedes-Benz Center. If you charge the batter-
ies yourself, follow the operating instructions for
your charging device.

638 Practical hintsBatteriesStarter battery
Connect the switched-off charging de-
vice to the terminals of the starter bat-
tery. Observe the operating
instructions in the manual for the
charging device while doing so.
Reinstalling starter battery
Install starter battery in engine com-
partment.

Swing retaining bar down.
Reconnecting starter battery

Make sure that the consumer battery in
the trunk is correctly installed and con-
nected.

Turn SmartKey in starter switch to po-
sition 0 and remove.

Connect the positive lead and fasten its
cover2 (
page 636).

Connect negative lead1
(page 636).

Attach ventilation tube.

Switch on the ignition (
page 315).

Start the engine (
page 359).

Check vehicle functions.
!
Only use charging devices with a maximum
charging voltage of 14.8 V.
Warning!
G
During the charge procedure, there is a risk
of acid burns due to gases escaping from
the battery. Do not bend over the battery
during the charge procedure.
!
The battery and the battery ventilation hose
must always be securely installed when the vehi-
cle is in operation.
!
Always connect the starter battery in the or-
der described below. Otherwise, the vehicle’s
electronics could be damaged.
Warning!
G
Do not drive without a properly installed and
connected consumer battery.
Have any work on the consumer battery car-
ried out by an authorized Mercedes-Benz
Center.
!
Never invert the terminal connections.
!
Make sure that the battery has a plug where
the ventilation tube is attached to it.

639 Practical hints
Jump starting
Jump starting
If the starter battery is discharged, the en-
gine can be started with jumper cables and
the battery of another vehicle. Observe the
following:

Jump starting should only be performed
when the engine and catalytic convert-
er are cold.


Do not start the engine if the battery is
frozen. Let the battery thaw out first.


Only use 12-volt battery to jump start
y o ur ve h i c l e . J u m p s t a r t i n g w i t h a m o r e
powerful battery could damage the ve-
hicle’s electrical system, which will not
be covered by the Mercedes-Benz Lim-
ited Warranty.


Only use jumper cables with sufficient
cross-section and insulated terminal
clamps.


Always make sure that the jumper ca-
bles are not on or near pulleys, fans or
other parts that move when an engine
is started or running.
Warning!
G
Failure to follow these directions will cause
damage to the electronic components, and
can lead to a battery explosion and severe
injury or death.
Never lean over batteries while connecting
or jump starting, you might get injured.
Battery fluid contains sulfuric acid. Do not
allow this fluid to come in contact with eyes,
skin or clothing. In case it does, immediately
flush affected area with water, and seek
medical help if necessary.
A battery will also produce hydrogen gas,
which is flammable and very explosive. Keep
flames or sparks away from battery, avoid
improper connection of jumper cables,
smoking, etc.
Attempting to jump start a frozen battery
can result in it exploding, causing personal
injury.
Read all instructions before proceeding.
!
Do not tow-start the vehicle.
!
Jump starting should only be performed on
the starter battery installed in the engine com-
partment.
Avoid repeated and lengthy starting attempts.
Do not attempt to start the engine using a bat-
tery quick charge unit.
If engine does not run after several unsuccessful
starting attempts, have it checked at the nearest
authorized Mercedes-Benz Center.
Excessive unburned fuel generated by repeated
failed starting attempts may damage the catalyt-
ic converter and may present a fire risk.
Make sure the jumper cables do not have loose
or missing insulation.
Make sure the cable clamps do not touch any
other metal part while the other end is still at-
tached to a battery.

640 Practical hintsJump startingJump starting should only be performed on
the starter battery. The starter battery is
located in the engine compartment on the
passenger side (
page 634).

Make sure the two vehicles do not
touch.

Secure vehicle in place with electric
parking brake.

Shift the automatic transmission toP.

Turn off all electrical consumers, ex-
cept hazard warning flashers or work
lights.

Open the hood (
page 492).

Start the engine of the vehicle with the
charged battery and run at idle speed.1Positive terminal of your vehicle’s
battery
2Positive terminal of other vehicle’s
battery
3Negative terminal of other vehicle’s
battery
4Negative clamp
Warning!
G
Keep flames or sparks away from battery.
Do not smoke.
Observe all safety instructions and precau-
tions when handling automotive batteries
(page 634).
i
Vehicles with KEYLESS-GO: remove the
KEYLESS-GO button (
page 316) and use the
SmartKey with KEYLESS-GO like a normal
SmartKey.

641 Practical hints
Jump starting

Remove red cover from positive
terminal 1.

Connect positive terminal2 of the
charged battery with positive
terminal1 of the discharged battery
with the jumper cable. Clamp cable to
charged battery2 first.

Connect negative terminal3 of
charged battery to jumper cables and
attach other end4 to a suitable
ground point on the vehicle.

Get into vehicle and start engine within
30 seconds.
If the starting attempt does not suc-
ceed: 
Turn the SmartKey in starter switch
to position 0.

Take out the SmartKey.

Turn off engine of donor vehicle, re-
start it and let it run at idle speed
for several minutes.

Disconnect the jumper cable during
this time.

Reconnect jumper cable as de-
scribed before.

Restart engine.

While the engine is running, switch off
several electrical consumers such as
the blower.

Disconnect jumper cables first from
ground point4 and negative
terminal3, then from positive
terminals1 and2.

Have the battery checked at the near-
est authorized Mercedes-Benz Center.
!
Never invert the terminal connections.

642 Practical hintsTowing the vehicleMercedes-Benz recommends that the vehi-
cle be transported with all wheels off the
ground using flatbed or appropriate wheel
lift/dolly equipment. This method is pref-
erable to other types of towing.
When circumstances do not permit the
recommended towing methods, the vehi-
cle may be towed with all wheels on the
ground or front wheels raised only so far as necessary to have the vehicle moved to a
safe location where the recommended
towing methods can be employed.!
Do not tow-start the vehicle.
!
Use flatbed or wheel lift/dolly equipment
with SmartKey in starter switch turned to posi-
tion 0.
Do not tow with sling-type equipment. Towing
with sling-type equipment over bumpy roads will
damage radiator and supports.
To prevent damage during transport, do not tie
down vehicle by its chassis or suspension parts.
Switch off the ESP
® (page 73), the tow-away
alarm (
page 76) and the automatic central
locking (page 313).
If the vehicle’s transmission is damaged, only
have it towed with the drive shaft disconnected.
!
Make sure that the electric parking brake is
released. If the electric parking brake is malfunc-
tioning, release it mechanically (
page 616).
!
In vehicles with KEYLESS-GO, insert the
SmartKey into the starter switch under the
KEYLESS-GO button and turn the SmartKey in
the starter switch to 0.
!
If the vehicle is towed with the front axle
raised, the engine must be shut off (SmartKey in
starter switch starter switch position 0 or 1).
Otherwise the ESP
®/ETS will immediately be en-
gaged and will apply the rear wheel brakes.
While towing, the battery must be connected and
charged. Otherwise:


you will not be able to switch on the ignition


you will not be able to engage the automatic
transmission in position N
When towing the vehicle with all wheels on the
ground, the automatic transmission must be
shifted to N and the SmartKey must be in starter
switch position2.
In vehicles with KEYLESS-GO*, you must use the
starter switch under the KEYLESS-GO* button
(
page 315).
When towing the vehicle with all wheels on the
ground or the front axle raised, the vehicle may
be towed only for distances up to 30 miles
(50 km) and at a speed not to exceed 30 mph
(50 km/h).
!
To be certain to avoid a possibility of dam-
age to the drivetrain, however, we recommend
the drive shaft be disconnected at the rear axle
drive flange for any towing beyond a short tow to
a nearby garage.

643 Practical hints
Towing the vehicle
Warning!
G
If circumstances require towing the vehicle
with all wheels on the ground, always tow
with a tow bar if:

the engine will not run


there is a malfunction in the brake sys-
tem


there is a malfunction in the power sup-
ply or in the vehicle’s electrical system
as that will be necessary to adequately con-
trol the towed vehicle.
Prior to towing the vehicle with all wheels on
the ground, make sure the SmartKey is in
starter switch position 2 and automatic
locking is deactivated (
page 223).
Warning!
G
With the engine not running, there is no
power assistance for the brake and steering
systems. In this case, it is important to keep
in mind that a considerably higher degree of
effort is necessary to brake and steer the ve-
hicle. Adapt your driving accordingly.i
The automatic transmission will remain
locked in position P and the SmartKey will not
turn in the starter switch if the consumer battery
is disconnected or discharged. See information
on the battery (
page 634) or on jump starting
(
page 639).
i
To signal turns while being towed with the
hazard warning flasher in use, turn SmartKey in
starter switch to position 2 and activate the com-
bination switch for the left or right turn signal in
the usual manner – only the selected turn signal
will operate.
Upon canceling the turn signal, the hazard warn-
ing flasher will operate again.
!
When towing the vehicle with all wheels on
the ground, please note the following:
With the automatic central locking activated and
the SmartKey in starter switch position 2, or
KEYLESS-GO* start/stop button (
page 317)
in position 2, the vehicle doors lock if the left
front wheel as well as the right rear wheel are
turning at vehicle speeds of approximately
9mph (15km/h) or more.
Switch off the tow-away alarm (
page 76).
To prevent the vehicle doors from locking, deac-
tivate the automatic central locking
(
page 313).
Towing of the vehicle should only be done using
the properly installed towing eye bolt. Never at-
tach tow cable, tow rope or tow rod to vehicle
chassis, frame or suspension parts.

659 Technical data
Electrical system
Electrical system
Model
S 550
S 600
Generator (alternator)
14 V/180 A
14 V/220 A
Starter motor
12 V/1.7 kW
12 V/1.7 kW
Starter battery
12 V/35 Ah
12 V/35 Ah
Electrical consumer battery
12 V/95 Ah
12 V/95 Ah
Spark plugs
NGK PLKR 6A
Bosch Y 7 MPP 33
NGK IFR 6Q-G
Electrode gap
0.031 in (0.8 mm)
0.028 in (0.7 mm)
Tightening torque
15 – 18 lb-ft (20 – 25 Nm)
18 – 22 lb-ft (25 – 30 Nm)