Loading ...
Loading ...
Loading ...
Advice
The main functions incorporated in the power
management system are battery diagnosis,
residual current management and
dynamic
po
w
er management.
Battery diagnosis
The battery diagnosis function constantly
registers the condition of the battery. Sen-
sors detect the battery voltage, battery cur-
rent and battery temperature. This enables
the system to calculate the current power lev-
el and charge condition of the battery.
Residual current management
The residual current management reduces
power consumption while the vehicle is
parked. It controls the supply of power to the
various electrical devices while the ignition is
switched off. The system takes the battery di-
agnosis data into consideration.
Depending on the power level of the battery,
switch off the individual electrical devices
one after the other to prevent the battery
from losing too much charge and to ensure
that the engine can be started reliably.
Dynamic power management
While the vehicle is moving, this function dis-
tributes the available power to the various
electrical devices and systems according to
their requirements. The power management
ensures that on-board systems do not con-
sume more electrical power than the alterna-
tor can supply, and thus maintains the maxi-
mum possible battery power level.
Note
●
Neither is the power management system
able to overcome the given physical limits.
Please remember that the power and useful
life of the battery are limited.
●
When there is a risk that the vehicle will
not start, the alternator power failure or low
battery charge level warning lamp will be
shown ››› p
age 71.
Flat battery
Starting ability has first priority.
Short trips, city traffic and low temperatures
all place a heavy load on the battery. In these
conditions a large amount of power is con-
sumed, but only a small amount is supplied.
The situation is also critical if electrical devi-
ces are in use when the engine is not run-
ning. In this case power is consumed when
none is being generated.
In these situations you will be aware that the
power management system is intervening to
control the distribution of electrical power.
When the vehicle is parked for long periods
If you do not drive your vehicle for a period of
several days or weeks, the power manage-
ment will gradually shut off the electrical de-
vices one by one or reduce the amount of cur-
rent they are using. This limits the amount of
power consumed and helps to ensure relia-
ble starting even after a long period. Some
convenience functions, such as remote vehi-
cle opening, may not be available under cer-
tain circumstances. These functions will be
restored when you switch on the ignition and
start the engine.
With the engine switched off
For example, if you listen to the sound sys-
tem with the engine switched off the battery
will run down.
If the energy consumption means there is a
risk that the engine will not start, a text will
appear in vehicles with a driver information
system*.
This driver indicator tells you that you must
start the engine so that the battery can re-
charge.
When the engine is running
Although the alternator generates electrical
power, the battery can still become dis-
charged while the vehicle is being driven.
This can occur when a lot of power is being
consumed but only a small amount supplied,
192
Loading ...
Loading ...
Loading ...