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 metal ob-
jects - cables) creates a short circuit - risk of damage to the battery, explo-
sion and burning of the battery, jets of acid spurting out.
■
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 consumers and disconnect the negative
terminal
.
■
“Quick-charging” the vehicle battery is dangerous and requires a special
charger and specialist knowledge.
■
We therefore recommend that vehicle batteries be “rapidly charged” by a
specialist garage.
CAUTION
On 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 164, Jump-starting using the battery from
another vehicle .
Replacing
Read and observe
and on page 147 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 you have the battery replaced by a specialist garage.
Disconnecting and reconnecting
Read and observe
and on page 147 first.
Disconnecting
›
Switch off the ignition.
›
First, disconnect the negative terminal
first, then the positive
terminal
of the battery.
Connecting›First, connect the positive first, then the negative battery terminal.
After disconnecting and re-connecting the vehicle battery, the following func-
tions or devices are partially or completely inoperative.Function / deviceCommissioningTime settings» page 31
CAUTION
■ Disconnect the vehicle battery only with the ignition turned off - there is a
risk of damaging the electrical system of the vehicle.■
Under no circumstances must the battery cables be connected incorrectly –
risk of a cable fire.
Note
■ After disconnecting and re-connecting the vehicle battery, we recommend
having the vehicle checked by a specialist to ensure that the full functionality
of all electrical systems is guaranteed.■
The data of the multi-function display will be reset.
Automatic load deactivation
Read and observe
and on page 147 first.
The vehicle's electrical system automatically prevents the battery from dis-
charging when the battery is being heavily used. This manifests itself by the
following. ▶ The idling speed is raised to allow the generator to deliver more electricity to
the electrical system.
▶ Where necessary, large convenience consumers such as seat heaters and
rear window heaters have their power limited or are shut off completely in
the event of an emergency.
CAUTION
■ Despite such intervention by the vehicle electric system management, the
vehicle battery may be drained. For example, when the ignition is switched on
a long time with the engine turned off or the side or parking lights are turned
on during longer parking.■
Consumers that are supplied via a 12-V power socket can cause the vehicle
battery to discharge when the ignition is switched off.
149Inspecting and replenishing
