Get Breakdown assistance -> Battery (vehicle) Guide for Mercedes C Class 4 Door Fourth Generation (2014-2021)

394 Breakdown assistance

Battery (vehicle)

Notes on the 12 V battery

&

WARNING Risk of an accident due to

work carried out incorrectly on the bat‐

tery

Work carried out incorrectly on the battery

can, for example, lead to a short circuit. This

can restrict functions relevant for safety sys‐

tems and impair the operating safety of your

vehicle.

You could lose control of the vehicle in the

following situations in particular:

#

To reduce the tyre pressure: press pres‐

sure release button 1 next to manometer

2.

Pull the tyre sealant bottle out of the tyre

inflation compressor. Press the locking tabs

on the yellow cap together to do this.

The filling hose stays on the tyre sealant bot‐

tle.

Drive to the nearest qualified specialist work‐

shop and have the tyre, tyre sealant bottle

and filling hose replaced there.

#

When the tyre pressure is correct, unscrew

the filling hose from the valve of the sealed

tyre.

Screw the valve cap onto the valve of the

sealed tyre.

R

when braking

R

in the event of abrupt steering manoeu‐

#

vres and/or when the vehicle's speed is

not adapted to the road conditions

#

In the event of a short circuit or a simi‐

lar incident, contact a qualified special‐

ist workshop immediately.

#

Do not drive on.

Breakdown assistance 395

All vehicles

The highly flammable gas mixture is created

while the battery is charging and during starting

assistance.

#

Always have work on the battery carried

out at a qualified specialist workshop.

ENVIRONMENTAL NOTE Environmental

damage due to improper disposal of bat‐

teries

+

R

Further information on ABS (/ page 185)

Further information on ESP^®(/ page 186)

&

WARNING Danger of chemical burns

from the battery acid

For safety reasons, Mercedes-Benz recommends

that you only use batteries which have been tes‐

ted and approved for your vehicle by Mercedes-

Benz.

Battery acid is caustic.

#

Avoid contact with the skin, eyes or

clothing.

Batteries contain pollutants. It is

illegal to dispose of them with the household

rubbish.

#

Do not lean over the battery.

All vehicles except vehicles with a lithium-

ion battery

#

Do not inhale battery gases.

#

Keep children away from the battery.

&

WARNING Risk of explosion due to elec‐

trostatic charge

#

Immediately rinse battery acid off thor‐

oughly with plenty of clean water and

seek medical attention immediately.

Dispose of batteries in an

environmentally responsible manner.

Take discharged batteries to a qualified

specialist workshop or to a collection

point for used batteries.

Electrostatic charge can ignite the highly

explosive gas mixture in the battery.

#

To discharge any electrostatic charge

that may have built up, touch the metal

vehicle body before handling the bat‐

tery.

If you have to disconnect the 12 V battery, con‐

tact a qualified specialist workshop.

Comply with safety notes and take protective

measures when handling batteries.

396 Breakdown assistance

Risk of explosion.

Observe this Owner's Manual.

NOTE Damage to the battery from over‐

voltage

*

When charging using a battery charger with‐

out a restriction of the maximum charging

voltage, the battery or the on-board electron‐

ics can be damaged.

Fire, naked flames and smoking are

prohibited when handling the battery.

Avoid creating sparks.

Observe the following if you do not intend to use

the vehicle over an extended period of time:

R

Activate standby mode.

#

Only use battery chargers with a maxi‐

mum charging voltage of 14.8 V.

R

Alternatively: connect the battery to a bat‐

Electrolyte or battery acid is corro‐

sive. Avoid contact with the skin, eyes

or clothing. Wear suitable protective

clothing, in particular gloves, an

apron and a face mask. Immediately

rinse electrolyte or acid splashes off

with clean water. Consult a doctor if

necessary.

tery charger approved by Mercedes-Benz or

consult a qualified specialist workshop to

disconnect the battery.

All other vehicles

When charging the battery and during starting

assistance, always use the jump-start connec‐

tion point in the engine compartment.

Notes on starting assistance and charging

the 12 V battery

NOTE Damage to the battery from over‐

voltage

*

Vehicles with a lithium-ion battery

Wear safety glasses.

When charging the battery and during starting

assistance, always use the jump-start connec‐

tion point in the engine compartment.

When charging using a battery charger with‐

out a restriction of the maximum charging

voltage, the battery or the on-board electron‐

ics can be damaged.

Keep children away.

#

Only use battery chargers with a maxi‐

mum charging voltage of 14.8 V.

Breakdown assistance 397

If the indicator/warning lamps in the instrument

cluster do not light up at low temperatures, it is

very likely that the discharged battery has fro‐

zen. In this case you may neither jump-start the

vehicle nor charge the battery.

The service life of a battery that has been

thawed may be dramatically shortened. The

starting characteristics may be impaired, espe‐

cially at low temperatures.

It is recommended that you have a thawed bat‐

tery checked at a qualified specialist workshop.

Plug-in hybrid: be sure to observe the notes in

the Supplement. You could otherwise fail to rec‐

ognise dangers.

&

WARNING Risk of explosion from hydro‐

gen gas igniting

WARNING Risk of explosion during

charging process and starting assistance

There is a danger of hydrogen gas igniting

when charging the battery if there is a short

circuit or sparks start to form.

During the charging process and starting

assistance, the battery may release an explo‐

sive gas mixture.

#

Make sure that the positive terminal of

the connected battery does not come

into contact with vehicle parts.

Never place metal objects or tools on a

battery.

The described order of the battery

clamps must be observed when con‐

necting and disconnecting the battery.

When giving starting assistance, always

make sure that you only connect bat‐

tery terminals with identical polarity.

Avoid fire, naked flames, creating

sparks and smoking.

Make sure there is sufficient ventila‐

tion.

#

Do not lean over a battery.

#

&

WARNING Risk of explosion from a fro‐

zen battery

#

All vehicles

A discharged battery may freeze at tempera‐

tures slightly above or below freezing point.

During starting assistance or battery charg‐

ing, battery gas can be released.

NOTE Damage caused by numerous or

extended attempts to start the engine

*

#

During starting assistance, you must

observe the described order for con‐

necting and disconnecting the jump

lead.

Numerous or extended attempts to start the

engine may damage the catalytic converter

due to non-combusted fuel.

#

Always allow a battery to thaw before

charging it or performing starting assis‐

tance.

#

Do not connect or disconnect the bat‐

tery clamps while the engine is running.

#

Avoid numerous and extended attempts

to start the engine.

398 Breakdown assistance

Observe the following points during starting

assistance and when charging the battery:

Observe the additional following points during

starting assistance:

R

Only use undamaged jump lead/charging

Starting assistance may only be provided

cables with a sufficient cross-section and

insulated terminal clamps.

using vehicles, batteries or other jump start

devices with a nominal voltage of 12 V.

R

Non-insulated parts of the terminal clamps

The vehicles must not touch.

must not come into contact with other metal

parts while the jump lead/charging cable is

connected to the battery/jump-start connec‐

tion point.

The jump lead/charging cable must not

come into contact with any parts which may

move when the engine is running.

R

Vehicles with a petrol engine: jump-start

the vehicle only when the engine and exhaust

system are cold.

#

Fold cover 1 up in the direction of the

arrow.

R

Starting assistance and charging the 12 V

battery

Requirements:

R

Always make sure that neither you nor the

battery is electrostatically charged.

R

The vehicle is secured with the electric park‐

ing brake.

Automatic transmission: the transmission

is in position j.

Manual transmission: the transmission is in

neutral.

The ignition and all electrical consumers are

switched off.

The bonnet is open.

R

Keep away from fire and naked flames.

Do not lean over the battery.

R

Observe the additional following points when

charging the battery:

R

Only use battery chargers tested and

approved for Mercedes-Benz.

Read the battery charger's operating instruc‐

tions before charging the battery.

R

Breakdown assistance 399

#

During starting assistance: start the

engine of the donor vehicle and run at idle

speed.

Connect the negative pole of the donor bat‐

tery and earth point 4 of your own vehicle

by using the jump lead/charging cable. Begin

with the donor battery first.

During starting assistance: start the

engine of your own vehicle.

During the charging process: start the

charging process.

During starting assistance: let the engines

run for several minutes.

During starting assistance: before discon‐

necting the jump lead, switch on an electrical

consumer in your own vehicle, e.g. the rear

window heater or lighting.

each time with the contacts on your own

vehicle first.

After removing the jump lead/charging

cable, close cover 2 of positive clamp 3.

#

Close cover 1.

Further information can be obtained at a quali‐

fied specialist workshop.

#

Replacing the 12 V battery

#

Observe the notes on the 12 V battery

(/ page 394).

Mercedes-Benz recommends that you have the

12 V battery replaced at a qualified specialist

workshop, e.g. at a Mercedes-Benz Service

Centre.

Observe the following notes if you want to

replace the battery yourself:

#

Slide cover 2 of positive clamp 3 on the

jump-starting connection point in the direc‐

tion of the arrow.

Connect positive clamp 3 on your vehicle to

the positive pole of the donor battery using

the jump lead/charging cable. Always begin

with positive clamp 3 on your own vehicle

first.

When the starting assistance/charging process

is complete:

R

Always replace a faulty battery with a battery

which meets the specific vehicle require‐

ments.

The vehicle is equipped with an AGM technol‐

ogy battery (Absorbent Glass Mat) or a lith‐

#

First, remove the jump lead/charging cable

from earth point 4 and negative pole of the

donor battery, then from positive clamp 3

and positive pole of the donor battery. Begin

Breakdown assistance -> Battery (vehicle) for Your Mercedes C Class 4 Door Fourth Generation (2014-2021)

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