If the battery continues to discharge, even with
the engine idling at a higher rpm setting, some
electrical loads will automatically be reduced. When
this occurs, the rear window defogger may take
slightly longer to clear the glass, the heated seats
may not get as warm as they usually do and the
climate control fan may cut back to a lower speed.
For more battery saving information, see “Battery
Saver Active Message” underDIC Warnings and
Messages on page 246.
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 put the charge
back in. When the state of charge is high, the
voltage is lowered slightly to prevent overcharging.
If the vehicle has a voltmeter gage or 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 loads are on: 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 or Service
Battery Charging System. If this message is
displayed, it is recommended that the driver reduce
the electrical loads as much as possible. SeeDIC
Warnings and Messages on page 246.
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