2003 MERCEDES-BENZ C320 COUPE battery

276 Practical hintsUnlocking/locking in an emergencyChanging batteries
If the batteries in the SmartKey card are
discharged, 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.SmartKey
1Mechanical key
2Battery compartment
Replacement batteries: Lithium, type
CR 2025 or equivalent.

Remove mechanical key (
page 274).

Insert the mechanical key in side open-
ing and push gray slide.
The battery compartment is unlatched.

Pull the battery compartment out of the
key housing in direction of arrow.
3Battery
4Contact spring

Remove the batteries.

Using a lint-free cloth, insert new bat-
teries under the contact spring with the
plus (+) side facing up.

Return battery compartment into hous-
ing until it locks in place.
Warning!
G
Keep the batteries out of reach of children.
If a battery is swallowed, seek medical help
immediately.
iWhen changing batteries, always re-
place both batteries.
The required replacement batteries are
available at any Mercedes-Benz
Center.

294 Practical hintsBattery
BatteryThe battery is located in the engine com-
partment on the right hand side.
Removal of filter box:
Release the three clamps1.

Remove filter box.
Installation of filter box:

Insert filter box properly.

Secure it with the three clamps1.
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 termi-
nal clamps while the engine is running
or the key is in the starter switch. Oth-
erwise the alternator and other elec-
tronic components could be severely
damaged.
Have the battery checked regularly by
an authorized Mercedes-Benz Center.
Refer to Service Booklet for mainte-
nance intervals or contact your autho-
rized 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 battery only to avoid the risk
of acid burns in the event of an accident.

295 Practical hints
Battery
Disconnecting the battery
Turn off all electrical consumers.

Open the hood (
page 226).

Remove the filter box.

Disconnect the battery negative lead.

Remove the cover from the positive ter-
minal.

Disconnect the battery positive lead.
Removing the batteries
Remove the screw-nuts securing the
battery.

Remove the battery bracket.

Take out the battery.
Charging and reinstalling batteries
Charge battery in accordance with the
instructions of the battery charger
manufacturer.

Reinstall the charged battery. Follow
the previously described steps in re-
verse order.
Reconnecting the batteries
Turn off all electrical consumers.

Connect the positive lead and fasten its
cover.

Connect the negative lead.

Reinstall the filter box.
Warning!
G
With a disconnected battery

y o u w i l l n o l o n g e r b e a b l e t o t u r n t h e k e y
in the starter switch


the selector lever will remain locked in
positionP
Warning!
G
Never charge a battery while still installed in
the vehicle. Gases may escape during charg-
ing and cause explosions that may result in
paint damage, corrosion or personal injury.
!NEVER invert the terminal connections!!The battery, its filler caps and the vent
tube must always be securely installed
when the vehicle is in operation.

296 Practical hintsBattery
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.
iThe following procedures must be car-
ried out following any interruption of
battery power (e.g. due to reconnec-
tion):

Set the clock (
page 116) (vehi-
cles with COMAND*: see COMAND
operator’s manual).


Resynchronize the ESP
(page 260).


Resynchronize side windows
(page 184).


Resynchronize panorama slid-
ing/pop-up roof (
page 188).

297 Practical hints
Jump starting
Jump starting
If the battery is discharged, the engine can
be started with jumper cables and the bat-
tery of another vehicle. Observe the follow-
ing:

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 jump start from batteries with the
same voltage rating (12V). Jump start-
ing with a more powerful battery could
damage the vehicle’s electrical system,
which will not be covered by the
Mercedes-Benz Limited Warranty.


Use only jumper cables with sufficient
cross-section and insulated terminal
clamps.


Always make sure that the jumper ca-
bels 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.
Read all instructions before proceeding.
!Jump starting may only be performed
on the battery installed in the engine
compartment.
Avoid repeated and lengthy starting at-
tempts.
Do not attempt to start the engine us-
ing a battery quick charge unit.
If engine does not run after several un-
successful starting attempts, have it
checked at the nearest authorized
Mercedes-Benz Center.
Excessive unburned fuel generated by
repeated failed starting attempts may
damage the catalytic 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 attached to a battery.

298 Practical hintsJump startingThe battery is located in the engine com-
partment on the right hand side. The
terminals for jump starting are located in
front of the battery.
Make sure that the two vehicles do not
touch.

Turn off the engine.
On both vehicles:

Turn off all electrical consumers.

Apply parking brake.

Shift selector lever to positionP (man-
ual transmission to Neutral).1Positive terminal of charged battery
2Positive under hood terminal in front of
discharged battery
3Negative terminal of charged battery
4Negative under hood terminal in front
of discharged battery

Connect positive terminal1 of the
charged battery with under hood
terminal2 in front of the discharged
battery with the jumper cables. Clamp
cable to charged battery1 first.

Start engine of the vehicle with the
charged battery and run at idle speed.

Connect negative terminal3 of the
charged battery with under hood
terminal4 in front of the discharged
battery with the jumper cables. Clamp
cable to charged battery3 first.

Start the engine of the disabled vehi-
cle.
After the engine has started, you can again
turn on the electrical consumers. Do not
turn on the lights under any circumstanc-
es.

Remove the jumper cables first from
negative terminals3 and4 and then
from positive terminals1 and2.

Have the battery checked at the
nearest authorized Mercedes-Benz
Center.
Warning!
G
Keep flames or sparks away from battery.
Do not smoke.
Observe all safety instructions and precau-
tions when handling automotive batteries
(page 231).
!Vehicles with automatic transmission:
Do not tow-start the vehicle.

301 Practical hints
Towing the vehicle
Warning!
G
With the engine not running, there is no
power assistance for the braking and steer-
ing systems. In this case, it is important to
keep in mind that a considerably higher de-
gree of effort is necessary to brake and
steer the vehicle. Adapt your driving accord-
ingly.
!When towing the vehicle with all wheels
on the ground, please note the follow-
ing:
With the automatic central locking acti-
vated and the key in starter switch
position2, the vehicle doors lock if the
left front wheel as well as the right rear
wheel are turning at vehicle speeds of
approx. 9 mph (15 km/h) or more.
Switch off the tow-away alarm
(page 79).
To prevent the vehicle doors from lock-
ing, deactivate the automatic central
locking (
page 122).
Towing of the vehicle should only be
done using the properly installed tow-
ing eye bolt. Never attach tow cable,
tow rope or tow rod to vehicle chassis,
frame or suspension parts.
iIf the battery is disconnected or dis-
charged

the key will not turn in the starter
switch. See notes on the battery
(page 294) or on jump starting
(page 297).


the selector lever will remain
locked in positionP. See notes on
manual unlocking of gear selector
lever (
page 277).

314 Technical dataElectrical system
Electrical systemModel
C230Kompressor
C320
Generator (alternator)
14 V/120 A
14 V/120 A
Starter motor
12 V/1.1 kW
12 V/1.7 kW
Battery
12V/100 Ah
12V/100 Ah
Spark plugs
Bosch F 6 MPP 332
Bosch F 8 DPP332
NGK PFR 5 R-11
Electrode gap
0.031 in (0.8 mm)
0.039 in (1.0 mm)
Tightening torque
18 – 22 ft.lb (25 - 30 Nm)
15 – 22 ft.lb (20 – 30 Nm)