Buick 2011 Lucerne - Manual (Page 170)

Black plate (14,1) Buick Lucerne Owner Manual - 2011
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 4‑49.
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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