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 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
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 idlespeed 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 3-49.
Battery Run-Down Protection
Your vehicle has a battery saver feature designed to
protect the vehicle’s battery.
When any interior lamp is left on and the ignition is
turned off, the battery rundown protection system will
automatically turn the lamp off after 20 minutes. This
will avoid draining the battery. This vehicle also has a
retained accessory power feature. If the radio is on,
it will turn off after 10 minutes or if any door on the
vehicle is opened. SeeRetained Accessory Power (RAP)
on page 2-21.
3-17
