SymbolMeaningKeep fire, sparks, open flames and lit cigarettes well clear of the
vehicle battery.When charging the vehicle battery, a highly explosive gas mixture
is produced.Keep children away from the vehicle battery.WARNINGThere is risk of injuries, poisoning, chemical burns, explosions or fire when
working on the battery and on the electrical system. It is essential to com-
ply with the generally applicable rules of safety as well as the warning in-
structions outlined below.■
Keep the vehicle battery away from people who are not completely inde-
pendent, especially children.
■
Do not tilt the battery otherwise battery electrolyte may flow out of the
battery vent openings. Protect your eyes by wearing safety goggles or a
face shield – risk of blindness!
■
Always wear protective gloves, eye and skin protection when handling
the vehicle battery.
■
The battery acid is strongly corrosive and must, therefore, be handled
with the greatest of care.
■
Corrosive fumes in the air irritate the air passages and lead to conjunctivi-
tis and inflammation of the air passages in the lungs.
■
Battery acid corrodes dental enamel and, if it comes into contact with the
skin, causes deep wounds that take a long time to heal. Repeated contact
with diluted acids causes skin diseases (inflammations, ulcers, skin cracks).
■
If any battery acid comes into contact with your eyes, rinse the affected
eye immediately with clean water for several minutes and consult a doctor
immediately!
■
Splashes of acid on your skin or clothes should be neutralised as soon as
possible using soap suds and then rinsed with plenty of water. If you swal-
low battery acid, consult a doctor immediately!
WARNING■ It is prohibited to work with naked flames or lights.■It is prohibited to smoke or carry out any activities that produce sparks.■
Never use a damaged vehicle battery – risk of explosion!
WARNING (Continued)■Never charge a frozen or thawed vehicle battery – risk of explosion and
chemical burns!■
Replace a frozen vehicle battery.
■
Never jump-start vehicle batteries with insufficient acid levels – risk of
explosion and chemical burns.
WARNING■ When you charge a battery, hydrogen is released, and a highly explosive
gas mixture is also produced. An explosion can be caused through sparkling
over during unclamping or loosening of the cable plug while the ignition is
on.■
Creating a bridge between the poles on the battery (e.g. with a metal ob-
ject or cable) creates a short circuit - risk of melting the lead bars, and risk
of explosion, battery fire and acid splashes.
■
Avoid creating sparks when working with cables and electrical devices.
Strong sparking represents a risk of injury.
■
Before carrying out any work on the electrical system, switch off the en-
gine, the ignition and all electrical components and disconnect the negative
terminal (-) on the battery.
CAUTION
Improper handling of the battery can lead to damage. We recommend having
all work on the vehicle battery carried out by a specialist garage.
CAUTION
■ The vehicle battery must only be disconnected if the ignition is switched off,
otherwise the vehicle's electrical system (electronic components) can be dam-
aged. When disconnecting the battery from the electrical system, first of all
disconnect the negative terminal (-) of the battery, and then the positive ter-
minal (+).■
When connecting the battery to the electrical system, first of all connect the
positive terminal (+) of the battery, and then the negative terminal (-). Under
no circumstances must the battery cables be connected incorrectly – risk of a
cable fire.
■
Ensure that battery acid does not come into contact with the bodywork – risk
of damage to the paintwork.
■
Do not place the battery in direct daylight in order to protect the vehicle bat-
tery housing from the effects of ultra-violet light.
194General Maintenance
CAUTIONFor technical reasons, on vehicles with the description “AGM”, the electrolyte
level cannot be checked.
Note
The battery acid level is also checked regularly by a specialist garage as part of
the inspection service.
Charging
Read and observe
and on page 194 first.
A properly charged vehicle battery is essential for reliably starting the engine.
›
Switch off the ignition and all of the electrical components.
›
Disconnect both battery cables (“negative” first, then “positive”) only when“rapid charging” the battery.
›
Attach the terminal clamps of the charger to the battery terminals (red =
“positive”, black = “negative”).
›
Plug the mains cable of the charger into the power socket and switch the
charger on.
›
Once charging is complete: Switch off the charger and remove the mains ca-
ble from the power socket.
›
Only then disconnect the charger's terminal clamps.
›
Reconnect the cables to the battery (first “positive”, then “negative”).
It is not necessary to disconnect the battery cables if you are recharging the
vehicle battery using low amperages (for example from a mini-charger). Refer
to the charger manufacturer's instructions .
A charging current of 0.1 multiple of the total vehicle battery capacity (or low-
er) must be used until full charging is achieved.
Both cables must be disconnected before charging the battery with high
amperages, known as “ rapid charging”.
The vent plugs of the vehicle battery should not be opened for charging.
WARNING“Quick-charging” the vehicle battery is dangerous and requires a special
charger and specialist knowledge.CAUTIONOn vehicles with the START/STOP system, the pole terminal of the charger
must not be connected directly to the negative terminal of the vehicle battery,
but only to the engine earth » page 212, Jump-starting in vehicles with the
START STOP system .
Note
We therefore recommend that vehicle batteries be rapid charged by a special-
ist garage.
Replacing
Read and observe
and on page 194 first.
The new vehicle battery must have the same capacity, voltage, current and
size as the original battery. Suitable vehicle battery types can be purchased
from a specialist garage.
We recommend having the battery replaced by a specialist garage, where the
new vehicle battery will be installed properly and the original battery will be
disposed of in accordance with national regulations.
Disconnecting or reconnecting
Read and observe
and on page 194 first.
The following functions are initially deactivated or are no longer able to oper-
ate faultlessly after the vehicle battery has been disconnected and reconnec-
ted.
FunctionOperating measureElectrical power window (operational faults)» page 64Panoramic sliding roof (operational faults)» page 218Enter the radio/navigation system code
number» User manual of the radio
or » user manual of the naviga-
tion systemSetting the clock» page 32Data in the multifunction display are de-
leted.» page 44 196General Maintenance
WARNING■If you cannot inflate the tyre to at least 2.0 bar, this means the damage
sustained was too serious. The sealing agent cannot be used to seal the
tyre.
Do not continue to drive! Seek help from a specialist garage.■
The tyre inflation hose and air compressor may get hot as the tyre is be-
ing inflated – there is a risk of burning.
CAUTION
Switch off the air compressor after running 8 minutes at the latest – there is a
risk of overheating. Allow the air compressor to cool a few minutes before
switching it on again.
Notes for driving with tyre repaired
Read and observe
on page 209 first.
The inflation pressure of the repaired tyre must be checked after driving for 10minutes.
If the tyre pressure is 1.3 bar or less
›
Do not continue to drive! You cannot properly seal with tyre with the
breakdown kit.
If the tyre pressure is 1.3 bar or more
›
Set the tyre pressure back to the correct value.
›
Continue driving carefully to the nearest specialist garage at a maximum speed of 80 km/h (50 mph).
Jump-starting
Introduction
This chapter contains information on the following subjects:
Jump-starting using the battery from another vehicle
211
Jump-starting in vehicles with the START STOP system
212
Jump-starting vehicles with the vehicle battery in the boot
212
The battery of another vehicle can be used to jump-start your vehicle if the en-
gine will not start because the battery is flat.
WARNING■ Pay attention to the warning instructions relating to work in the engine
compartment » page 186.■
A discharged vehicle battery may already freeze at temperatures just be-
low 0 °C. If the battery is frozen, do not jump-start with the battery of an-
other vehicle – there is a risk of explosion.
■
Keep any sources of ignition (naked flame, smouldering cigarettes, etc.)
away from the battery – risk of explosion!
■
Never jump-start vehicle batteries with insufficient acid levels – risk of
explosion and chemical burns.
■
The vent screws of the battery cells must be tightened firmly.
Note
We recommend you buy jump-start cables from a car battery specialist.
Jump-starting using the battery from another vehicle
Fig. 184
Jump-starting: A – flat battery, B
– battery providing current
Read and observe on page 211 first.
The starting process using the battery of another vehicle requires the use of
jumper cables.
The jump-start cables must be attached in the following sequence.
›
Attach clamp
1
to the positive terminal of the discharged battery
A
» Fig. 184 .
›
Attach clamp
2
to the positive terminal of the battery supplying power
B
.
›
Attach clamp
3
to the negative terminal of the battery supplying power
B
.
›
Attach clamp
4
to a solid metal component firmly connected to the engine
block or to the engine block itself.
Starting engine
›
Start the engine on the vehicle providing the power and allow it to idle.
211Emergency equipment and self-help
›Start the engine of the vehicle with the discharged battery.›If the engine does not start, halt the attempt to start the engine after 10 sec-
onds and wait for 30 seconds before repeating the process.›
Remove the jumper cables exactly in the reverse sequence as for clamping.
Both batteries must have a rated voltage of 12 V. The capacity (Ah) of the bat-
tery supplying the power must not be significantly less than the capacity of
the discharged battery in your vehicle.
Jump-start cables
Only use jump-start cables which have an adequately large cross-section and
insulated terminal clamps. Obey the instructions of the jump-start cable manu-
facturer.
Positive cable - colour coding in the majority of cases is red.
Negative cable - colour coding in the majority of cases is black.
WARNING■
Do not clamp the jump-start cable to the negative terminal of the dis-
charged battery. There is the risk of detonating gas seeping out the battery
being ignited by the strong spark which results from the engine being star-
ted.■
The non-insulated parts of the terminal clamps must never touch each
other – there is a risk of short circuit.
■
The jump-start cable connected to the positive terminal of the battery
must not come into contact with electrically conducting parts of the vehicle
– there is a risk of short circuit.
■
Route the jump-start cables so that they cannot be caught by any rotat-
ing parts in the engine compartment.
■
There must not be any contact between the two vehicles otherwise cur-
rent may flow as soon as the negative terminals are connected.
Jump-starting in vehicles with the START STOP systemFig. 185
Engine earth: START STOP sys-
tem
Read and observe on page 211 first.
The jump-start cable must only be connected to the engine earthing point on vehicles with the START STOP system » Fig. 185.
Jump-starting vehicles with the vehicle battery in the boot
Fig. 186
Detail of the engine compart-
ment: Jump-starting point
Read and observe on page 211 first.
On vehicles with the vehicle battery in the boot, the positive terminal of the
battery supplying the power can only be connected to the jump-starting point
in the engine compartment of the vehicle being started by means of a jump-
start cable » Fig. 186.
›
Open the protective cap of the jump-starting point in the direction of the ar-
row » Fig. 186 .
›
Connect the positive terminal of the battery supplying the power with the
jump-starting point.
›
Attach the negative terminal of the battery supplying the power to a solid
metal part firmly connected to the engine block or to the engine block itself.
›
Start the engine.
212Do-it-yourself