Saturn 2010 AURA - Manual (Page 166)

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 gage 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 4-42.
Battery Run-Down Protection
The battery run-down feature is designed to protect the
vehicle’s battery.
When any interior lamp (trunk, reading lamps, or dome
lamp) is left on when the ignition is turned off, the
battery run-down protection system automatically shuts
the lamp off after 20 minutes. This prevents draining
of the battery.
To reactivate the interior lamps, do one of the following:
• Open any door.
• Press any Remote Keyless Entry (RKE) transmitter
button.
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