When you start the engine after the 12-volt battery has been totally discharged or after a
successful jump start, you may find that system settings (time, date, personal convenience settings
and programming) have been changed or deleted. Check and correct the settings as necessary
once the 12-volt vehicle battery has been sufficiently charged.
Checking the electrolyte level of the 12-volt vehicle battery
Fig. 232
In the engine compartment: folding open the 12-volt vehicle battery cover.
Fig. 233
Battery window on the top of the 12-volt vehicle battery (illustration).
First read and observe the introductoryinformation and safety warnings
⇒
Introduction
The electrolyte level of the 12-volt vehicle battery should be checked regularly in high-mileage
vehicles, in hot countries and in older 12-volt vehicle batteries. The 12-volt vehicle battery is
otherwise maintenance-free.
Any work on the 12-volt vehicle battery and the electrical system can cause serious
chemical burns, fire or electric shocks. Always read the following warnings and safety
information before carrying out any kind of work:
• Switch off the ignition and all electrical consumers before carrying out any work on the
12-volt vehicle battery and also disconnect the negative cable from the 12-volt vehicle
battery.
• Children should always be kept away from electrolyte and the 12-volt vehicle battery.
• Always wear eye protection and protective gloves.
• Electrolyte is very aggressive. It can burn the skin and can cause blindness. When
working with the 12-volt vehicle battery, ensure that your hands, arms and face in
particular are protected from acid spillages.
• Do not smoke during the work, and never work near naked flames or sparks.
• When handling cables and electrical equipment, avoid generating sparks and
electrostatic charge.
• Never short circuit the battery poles.
• Never use a damaged 12-volt vehicle battery. It can explode. Damaged 12-volt vehicle
batteries must be replaced as soon as possible.
• Damaged or frozen 12-volt vehicle batteries must be replaced as soon as possible.
Discharged 12-volt vehicle batteries can already freeze at temperatures of around
0°C (+32°F).
• In vehicles with the 12-volt vehicle battery in the luggage compartment, ensure that the
breather hose is connected properly to the 12-volt vehicle battery.
WARNING
• Do not expose the 12-volt vehicle battery to direct daylight for an extended period as
the UV rays could damage the battery housing.
• If the vehicle is left standing in cold conditions for a long period, protect the 12-volt
vehicle battery from frost. If it freezes, it will be destroyed.
NOTICE
