Owners manual...
Battery Voltage : Displays the current
battery voltage. The battery voltage
can fluctuate while viewing this
information on the DIC. This is
normal.
Battery Load Management
The vehicle has Electric Power
Management (EPM), which 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, 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 DIC
message might be displayed. If a
battery message is displayed, it is
recommended that the driver reduce
the electrical loads as much as
possible.
