2007 MERCEDES-BENZ CL-CLASS key battery

639 Practical hints
Replacing SmartKey batteries
Replacing SmartKey batteries
If the batteries in the SmartKey/SmartKey
with KEYLESS-GO* are discharged, the ve-
hicle can no longer be locked or unlocked.
It is recommended to have the batteries re-
placed at an authorized 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.SmartKey/SmartKey with
KEYLESS-GO*
Replacement batteries: Lithium, type
CR 2025 or equivalent.
Remove the mechanical key out of the
SmartKey/SmartKey with
KEYLESS-GO* (
page 635).
1Mechanical key
2Battery compartment
Insert mechanical key 1 into opening.
Press mechanical key 1 in direction of
arrow.
The battery compartment is unlatched.
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.
iWhen inserting the batteries, make sure
they are clean and free of lint.
iWhen changing batteries, always replace
both batteries.
The required replacement batteries are available
at any authorized Mercedes-Benz Center.

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640 Practical hints
Replacing SmartKey batteries
Pull battery compartment 2 out of the
housing.
3Batteries
4Contact springs
Pull out batteries3.
Using a line-free cloth, insert new bat-
teries 3 under contact springs 4 with
the positive terminal (+) side facing up.
Return battery compartment 2
(
page 639) into housing until it locks
into place.
Slide the mechanical key back into the
SmartKey/SmartKey with
KEYLESS-GO*.
Check the operation of the SmartKey/
SmartKey with KEYLESS-GO*.

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657 Practical hints
Batteries
Starter battery (example illustration from
CL 550)
1Negative terminal
2Positive terminal
Disconnecting starter battery
Secure vehicle in place with electronic
parking brake (
page 384).
Shift the automatic transmission toP
(
page 389).
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 658)
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.
iOnly 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.
iRemove SmartKey from starter switch (vehi-
cles with KEYLESS-GO*: Make sure the vehicle’s
on-board electronics have status 0)
(
page 336) 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.
iIf the consumer battery is discharged, you
must use the mechanical key to unlock the vehi-
cle (
page 635). 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.
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658 Practical hints
Batteries
Switching off vehicle’s internal
electrical functions
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 512).
Use a 10-mm open-end wrench to dis-
connect the battery negative lead.
Remove cover2 (page 657) 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
iVehicles with KEYLESS-GO: remove the
KEYLESS-GO button (
page 337) and use the
SmartKey with KEYLESS-GO like a normal
SmartKey.
!Do not remove the SmartKey!
iFor 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.
iHave the batteries charged by a
Mercedes-Benz Center. If you charge the batter-
ies yourself, follow the operating instructions for
your charging device.
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659 Practical hints
Batteries
Starter 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 657).
Connect negative lead1
(
page 657).
Attach ventilation tube.
Switch on the ignition (page 336).
Start the engine (page 378).
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.
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661 Practical hints
Jump starting
Jump starting should only be performed on
the starter battery. The starter battery is
located in the engine compartment on the
passenger side (
page 657).
Make sure the two vehicles do not
touch.
Secure vehicle in place with electronic
parking brake (
page 384).
Shift the automatic transmission toP
(
page 389).
Turn off all electrical consumers, ex-
cept hazard warning flashers or work
lights.
Open the hood (page 512).
Start the engine of the vehicle with the
charged battery and run at idle speed.1Negative clamp
2Negative terminal of charged battery
3Positive terminal of charged battery
4Positive terminal of discharged battery
Warning!G
Keep flames or sparks away from battery.
Do not smoke.
Observe all safety instructions and precau-
tions when handling automotive batteries
(
page 655).
iVehicles with KEYLESS-GO: remove the
KEYLESS-GO button (
page 337) and use the
SmartKey with KEYLESS-GO like a normal
SmartKey.

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662 Practical hints
Jump starting
Remove red cover from positive
terminal4.
Connect positive terminal3 of the
charged battery with positive
terminal4 of the discharged battery
with the jumper cable. Clamp cable to
charged battery3 first.
Connect negative terminal2 of
charged battery to jumper cables and
attach other end of the jumper cable
with the negative clamp1 to a suit-
able 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 nega-
tive clamp1 from ground point and
negative terminal2, then from posi-
tive terminals4 and3.
Have the battery checked at the near-
est authorized Mercedes-Benz Center.!Never invert the terminal connections.

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664 Practical hints
Towing the vehicle
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
vehicle. Adapt your driving accordingly.
!When towing the vehicle with all wheels on
the ground or with the front axle raised, the start-
er battery must be connected and charged. Oth-
erwise:

you will not be able to switch on the ignition

you will not be able to engage the automatic
transmission in positionN (
page 394)

you cannot release the electronic parking
brake
For information on charging the starter battery
see “Batteries” (
page 655) or see “Jump start-
ing” (
page 660).
!Make sure that the electronic parking brake
is released. If the electronic parking brake is
malfunctioning, release it mechanically
(
page 637).
!If the vehicle is towed with the front axle
raised, the automatic transmission must be in
positionN and the engine must be shut off
(SmartKey or SmartKey with KEYLESS-GO* in
starter switch position0 or1). Active braking
action through the ESP
® may otherwise
seriously damage the brake system.
!When towing the vehicle with all wheels on
the ground, the automatic transmission must be
shifted to positionN and the SmartKey or
SmartKey with KEYLESS-GO* must be in starter
switch position2.
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).
!If the vehicle is towed with all wheels on the
ground or with the front axle raised, the trans-
mission must be in positionN.
If you turn off the engine using

the SmartKey and

remove the SmartKey from the starter
switch
or

open a door

the KEYLESS-GO* start/stop button and
open a door
the transmission will shift to park position P
automatically.
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