2007 MERCEDES-BENZ SL55AMG battery

366 Practical hintsWhat to do if …Left display
Right display
Possible cause/consequence
Possible solution
#
Battery/Alternator
Stop car
The battery is malfunctioning.
The electro-hydraulic brake system
requires electrical energy and
therefore has only limited opera-
tion. Considerably greater brake
pedal force is required and the stop-
ping distance is increased.

Stop the vehicle in a safe location. Adjust driv-
ing to be consistent with reduced braking re-
sponsiveness.

Contact an authorized Mercedes-Benz Cen-
ter.
2
Brake wear
The brake pads have reached their
wear limit.

Have the brake pads replaced as soon as pos-
sible.
USA only:;Canada only:3
Reduced
brake effect
Start engine
The battery has insufficient voltage
and cannot supply sufficient power
to the electro-hydraulic brake sys-
tem.

Start the engine.
The message disappears when sufficient
voltage is available.
!
Brake pad thickness must be visually
checked by a qualified technician at the intervals
specified in the Maintenance Booklet.
Warning!
G
Inhalation of exhaust gas is hazardous to
your health. All exhaust gas contains carbon
monoxide (CO), and inhaling it can cause un-
consciousness and lead to death.
Do not run the engine in confined areas
(such as a garage) which are not properly
ventilated.

379 Practical hints
What to do if …
Left display
Right display
Possible cause/consequence
Possible solution
F
Key
not detected
The SmartKey with KEYLESS-GO* is
not recognized while the engine is
running because:

The SmartKey with
KEYLESS-GO* is not in the vehi-
cle.


There is strong radio-frequency
interference.

Stop the vehicle in a safe location or as soon
as it is safe to do so.

Search for the SmartKey with KEYLESS-GO*.
Otherwise the vehicle cannot be centrally
locked nor can the engine be started again af-
ter the engine is stopped.

Operate the vehicle with the SmartKey with
KEYLESS-GO* in the starter switch
Key
not detected
The SmartKey with KEYLESS-GO* is
not recognized when attempting to
start the engine with the
KEYLESS-GO start/stop button* on
the gear selector lever because:

The SmartKey with
KEYLESS-GO* is not in the vehi-
cle.


The battery in the SmartKey
with KEYLESS-GO* is not insert-
ed properly or completely dis-
charged.

Change the position of the SmartKey with
KEYLESS-GO* in the vehicle.

Make sure the batteries in the SmartKey with
KEYLESS-GO* are properly inserted
(page 395) and are not discharged
(page 110).

Start the engine with the SmartKey with
KEYLESS-GO* in the starter switch if
necessary.

395 Practical hints
Replacing SmartKey batteries
Replacing SmartKey batteries
If the batteries in the SmartKey or the
SmartKey with KEYLESS-GO* are dis-
charged, the vehicle can no longer be
locked or unlocked. It is recommended to
have the batteries replaced at an autho-
rized Mercedes-Benz Center.Batteries contain materials that can harm
the environment if disposed of improperly.
Recycling of batteries is the preferred
method of disposal. Many states require
sellers of batteries to accept old batteries
for recycling.

Remove the mechanical key from the
SmartKey or SmartKey with
KEYLESS-GO* (
page 391).
1Mechanical key
2Battery compartment

Insert mechanical key 1 into opening.

Press mechanical key 1 in direction of
arrow.
The battery compartment is unlatched.

Pull battery compartment 2 out of the
housing.
Warning!
G
Batteries contain poisonous and corrosive
substances. Therefore keep the batteries
out of reach of children.
If a battery is swallowed, seek medical help
immediately.
i
When inserting batteries, make sure they
are clean and free of lint.
i
When replacing batteries, always replace
both batteries.
The required replacement batteries (Lithium,
type CR 2025 or equivalent) are available at any
authorized Mercedes-Benz Center.


396 Practical hintsReplacing SmartKey batteries3Batteries
4Contact spring
Pull out batteries3.

Using a lint-free cloth, insert new bat-
teries 3 under contact springs 4 with
the positive terminal (+) side facing up.

Return battery compartment 2 into
housing until it locks into place.

Slide mechanical key 1 back into
SmartKey or SmartKey with
KEYLESS-GO*.

Check the operation of the SmartKey
or SmartKey with KEYLESS-GO* as well
as the KEYLESS-GO* function.


414 Practical hintsBatteriesFor more information on batteries, see
“Battery” (
page 281).
Your vehicle is equipped with two
batteries:


The starter battery


The battery for electrical consumers
(consumer battery), located in the
trunk
The starter battery is located on the
right-hand side of the engine compart-
ment.
1Positive terminal
2Negative terminal
3Battery ventilationThe consumer battery is located on the
right-hand side of the trunk.
4Positive terminal
5Negative terminal
!
The starter battery, its filler caps, and the
ventilation hose must always be securely in-
stalled when the vehicle is in operation.
!
The consumer battery located in the trunk is
a valve-regulated lead acid (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.

415 Practical hints
Batteries
!
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
factory-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.
!
Never loosen or detach battery terminal
clamps while the engine is running or the
SmartKey is in the starter switch. Otherwise the
alternator and other electronic components
could be severely damaged.
Have the starter battery checked regularly by an
authorized Mercedes-Benz Center.
Refer to Maintenance Booklet for maintenance
intervals or contact an authorized
Mercedes-Benz Center for further information.
Warning!
G
Do not place metal objects on the battery as
this could result in a short circuit.
Use leak-proof batteries only to avoid the
risk of acid burns in the event of an acci-
dent.
Warning!
G
The brake system requires electrical power
to operate.
A malfunction in the vehicle’s power supply
or electrical system may impair brake sys-
tem operation and switch it into its emer-
gency operation mode. The same applies if
battery is disconnected. To brake, the driver
must then apply significantly greater brake
pedal pressure and depress the pedal much
further to obtain the expected braking ef-
fect. If necessary, apply full pressure to the
brake pedal. Brakes are only applied to the
front wheels. Stopping distance is in-
creased! Adjust your driving style according-
ly. For more information, see
“Electro-hydraulic brake system”
(page 92).

416 Practical hintsBatteries
Disconnecting the batteries
Apply the parking brake (
page 61).

Make sure the gear selector lever is set
to position P (
page 168).

Close the retractable hardtop
(page 199).

Turn off all electrical consumers.

Turn off the engine (
page 62).

Remove the SmartKey from the starter
switch.
Vehicles with KEYLESS-GO*: Open
the driver’s door.

Open the trunk.

Read and observe safety instructions
and precautions (
page 281).

Open the luggage cover in the trunk
(page 206).

Remove the trunk floor.
The battery for electrical consumers is
located in the right hand area of the
trunk (
page 388).

Use the 10 mm open-end wrench from
the vehicle tool kit to disconnect the
negative lead from negative
terminal5 of the consumer battery
(page 414).
Warning!
G
With a disconnected battery

you will no longer be able to turn the
SmartKey in the starter switch and
pressing the KEYLESS-GO* start/stop
button on the gear selector lever will
have no effect


the gear selector lever will remain
locked in positionP
!
Always disconnect the batteries in the order
described below, even if you only want to charge
the starter battery, for example. Otherwise the
vehicle’s electronics can be damaged.

417 Practical hints
Batteries

Open the hood (
page 274).

Use the 10 mm open-end wrench from
the vehicle tool kit to disconnect the
negative lead from negative
terminal2 of the starter battery
(page 414).

Remove the covers from the positive
terminals 1 and 4 (
page 414).

Disconnect the positive lead from pos-
itive terminal 4 of the consumer bat-
tery (
page 414).

Disconnect the positive lead from pos-
itive terminal 1 of the starter battery
(page 414).
Removing the batteries
Removing the consumer battery
Remove the screws securing the bat-
tery in the trunk.

Remove the battery support and
bracket.

Pull out the battery ventilation hose
from the battery.
Depending on battery arrangement in
your vehicle model, the ventilation tube
is located either on the left or right side
of the battery.

Take out the battery.
Removing the starter battery

Remove the screws securing the start-
er battery in the engine compartment.

Pull battery ventilation 3
(page 414) out of the battery.

Lift the retaining bracket.

Remove the battery.
Charging and reinstalling batteriesWarning!
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.