Consumer battery MERCEDES-BENZ S550 2007 W221 Owner's Manual

315 Controls in detail
Starter switch positions
Starter switch positions
SmartKeyStarter switch
0For removing SmartKey
1Power supply for some electrical con-
sumers, such as seat adjustment
2Ignition (power supply for all electrical
consumers) and driving position.
All lamps (except high beam headlamp
indicator lamp and turn signal indicator
lamps unless activated) in the instru-
ment cluster come on. If a lamp in the
instrument cluster fails to come on
when the ignition is switched on, have
it checked and replaced if necessary.
If a lamp in the instrument cluster re-
mains on after starting the engine or
comes on while driving, refer to “Lamps
in instrument cluster” (
page 544).
3Starting positionFor information on starting the engine us-
ing the SmartKey, see “Starting with the
SmartKey” (
page 359).
Warning!
G
When leaving the vehicle, always remove the
SmartKey or SmartKey with KEYLESS-GO*
from the starter switch, take it with you, and
lock the vehicle. Do not leave children unat-
tended in the vehicle, or with access to an
unlocked vehicle. Unsupervised use of vehi-
cle equipment may cause an accident
and/or serious personal injury.
i
When you switch on the ignition, the indica-
tor and warning lamps (except high beam head-
lamp indicator lamp and turn signal indicator
lamps unless activated) in the instrument cluster
come on. The indicator and warning lamps (ex-
cept high beam headlamp indicator lamp and
turn signal indicator lamps if activated) should go
out when the engine is running. This indicates
that the respective systems are operational.
i
When the SmartKey is removed from the
starter switch and the automatic transmission is
in a position other thanP, the automatic trans-
mission automatically shifts to P.
!
If the SmartKey cannot be turned in the
starter switch, the battery may not be sufficient-
ly charged.


Check the battery and charge it if necessary
(page 634).


Get a jump start (
page 639).
To prevent accelerated battery discharge or a
completely discharged battery, always remove
the SmartKey from the starter switch when the
engine is not in operation.

430 Controls in detailAutomatic climate controlDeactivating
Press button; (
page 426) up or
down.
The indicator lamp on the button goes
out.
The previous settings are once again in
effect, except air recirculation mode
stays off.
Windshield fogged on the outside

Switch the windshield wipers on
(page 351).

Press buttonU (
page 426) up or
down.
The indicator lamp on the button
comes on.
Rear window defroster
Activating
Switch on the ignition (
page 315).

Press button< (
page 426) up or
down.
The indicator lamp on the button
comes on.
Deactivating

Press button< (
page 426) up or
down.
The indicator lamp on the button goes
out.
Maximum cooling MAXCOOL (USA only)
If U is selected on both the left and
right side and there is a high demand for
cooling, the display “MAXCOOL” appears
in the COMAND display.
This provides the fastest possible cooling
of the vehicle interior (when windows and
tilt/sliding sunroof or tilt/sliding panel*
are closed).
!
The rear window defroster uses a large
amount of power. To keep battery drain to a min-
imum, switch off the defroster as soon as the
rear window is clear.
i
The defroster is automatically deactivated
after some time of operation depending on the
outside temperature.Warning!
G
Any accumulation of snow and ice should be
removed from the rear window before driv-
ing. Visibility could otherwise be impaired,
endangering you and others.
i
If the rear window defroster switches off too
soon and the indicator lamp goes out, this indi-
cates that too many electrical consumers are op-
erating simultaneously and the load on the
battery is reducing available voltage. The system
responds automatically by deactivating the rear
window defroster.
i
Maximum cooling MAXCOOL is only avail-
able when the engine is running.

634 Practical hintsBatteriesYour vehicle is equipped with two batter-
ies:

The starter battery (located in the en-
gine compartment)


The battery for electrical consumers
(located in the trunk)
The batteries should always be sufficiently
charged in order to achieve its rated ser-
vice life. Refer to Maintenance Booklet for
battery maintenance intervals.
If you use your vehicle mostly for short-dis-
tance trips, you will need to have the bat-
tery charge checked more frequently.
When replacing the batteries, always use
batteries approved by Mercedes-Benz.
If you do not intend to operate your vehicle
for an extended period of time, consult an
authorized Mercedes-Benz Center about
steps you need to observe.Batteries contain materials that can harm
the environment if disposed of improperly.
Large 12-volt storage batteries contain
lead. Recycling of batteries is the preferred
method of disposal. Many states require
sellers of batteries to accept old batteries
for recycling.
!
Do not tow-start the vehicle.
Warning!
G
Observe all safety instructions and precau-
tions when handling automotive batteries.
Risk of explosion.
Fire, open flames and smoking
are prohibited when handling
batteries. Avoid creating sparks.
Battery acid is caustic. Do not
allow it to come into contact
with skin, eyes or clothing.
Wear suitable protective cloth-
ing, especially gloves, apron and
faceguard.
Wear eye protection.
Rinse any acid spills immediate-
ly with clear water. Contact a
physician if necessary.
Keep children away.
Follow the instructions in this
Operator’s Manual.

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.

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.

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.