alternator BUICK LUCERNE 2010 Owner's Manual

Electric Power Management
The vehicle has Electric Power Management (EPM) that
estimates the battery's temperature and state of charge.
It then adjusts the voltage for best performance and
extended life of the battery.
When the battery's state of charge is low, the voltage is
raised slightly to quickly bring the charge back up.
When the state of charge is high, the voltage is lowered
slightly to prevent overcharging. If the vehicle has a
voltmeter gauge or a voltage display on the Driver
Information Center (DIC), you may see the voltage
move up or down. This is normal. If there is a problem,
an alert will be displayed.
The battery can be discharged at idle if the electrical
loads are very high. This is true for all vehicles. This is
because the generator (alternator) may not be spinning
fast enough at idle to produce all the power that is
needed for very high electrical loads.
A high electrical load occurs when several of the
following are on, such as: headlamps, high beams, fog
lamps, rear window defogger, climate control fan at high
speed, heated seats, engine cooling fans, trailer loads,
and loads plugged into accessory power outlets.EPM works to prevent excessive discharge of the
battery. It does this by balancing the generator's output
and the vehicle's electrical needs. It can increase
engine idle speed to generate more power, whenever
needed. It can temporarily reduce the power demands
of some accessories.
Normally, these actions occur in steps or levels, without
being noticeable. In rare cases at the highest levels of
corrective action, this action may be noticeable to the
driver. If so, a Driver Information Center (DIC) message
might be displayed, such as BATTERY SAVER
ACTIVE, BATTERY VOLTAGE LOW, or LOW
BATTERY. If this message is displayed, it is
recommended that the driver reduce the electrical loads
as much as possible. See
DIC Warnings and Messages
on page 4‑55.
Inadvertent Power Battery Saver
This feature is designed to protect your vehicle's battery
against drainage from the interior lamps, or garage
door opener. When the ignition is turned off, the power
to these features will automatically turn off after
10 minutes. Power will be restored for an additional
10 minutes if any door is opened, the trunk is opened or
the courtesy lamp switch is turned on.
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