Electric Power ManagementThe vehicle has Electric Power Management (EPM) thatestimates the battery’s temperature and state ofcharge. It then adjusts the voltage for best performanceand extended life of the battery.When the battery’s state of charge is low, the voltage israised slightly to quickly put the charge back in. Whenthe state of charge is high, the voltage is lowered slightlyto prevent overcharging. If the vehicle has a voltmetergage or a voltage display on the Driver InformationCenter (DIC), you may see the voltage move upor down. This is normal. If there is a problem, an alertwill be displayed.The battery can be discharged at idle if the electricalloads are very high. This is true for all vehicles. This isbecause the generator (alternator) may not bespinning fast enough at idle to produce all the powerthat is needed for very high electrical loads.A high electrical load occurs when several of thefollowing loads are on: headlamps, high beams, foglamps, rear window defogger, climate control fan at highspeed, heated seats, engine cooling fans, trailerloads, and loads plugged into accessory power outlets.EPM works to prevent excessive discharge of thebattery. It does this by balancing the generator’s outputand the vehicle’s electrical needs. It can increaseengine idle speed to generate more power, wheneverneeded. It can temporarily reduce the power demands ofsome accessories.Normally, these actions occur in steps or levels, withoutbeing noticeable. In rare cases at the highest levelsof corrective action, this action may be noticeable to thedriver. If so, a Driver Information Center (DIC)message might be displayed, such as Battery SaverActive or Service Battery Charging System. If thismessage is displayed, it is recommended that the driverreduce the electrical loads as much as possible. SeeDIC Warnings and Messages on page 3-53.Battery Run-Down ProtectionThis feature shuts off the dome lamps if they are left onfor more than 10 minutes when the ignition is in LOCK.This will help prevent the battery from running down.3-23
