Electric Power ManagementThe vehicle has Electric Power Management(EPM) that estimates the battery’s temperature andstate of charge. It then adjusts the voltage forbest performance and extended life of the battery.When the battery’s state of charge is low, thevoltage is raised slightly to quickly put the chargeback in. When the state of charge is high, thevoltage is lowered slightly to prevent overcharging.If the vehicle has a voltmeter gage or voltagedisplay on the Driver Information Center (DIC), youmay see the voltage move up or down. This isnormal. If there is a problem, an alert will bedisplayed.The battery can be discharged at idle if theelectrical loads are very high. This is true for allvehicles. This is because the generator (alternator)may not be spinning fast enough at idle toproduce all the power that is needed for very highelectrical loads.A high electrical load occurs when several of thefollowing loads are on: headlamps, high beams, foglamps, rear window defogger, climate control fan athigh speed, heated seats, engine cooling fans,trailer loads, and loads plugged into accessorypower outlets.EPM works to prevent excessive discharge of thebattery. It does this by balancing the generator’soutput and the vehicle’s electrical needs. Itcan increase engine idle speed to generate morepower, whenever needed. It can temporarilyreduce the power demands of some accessories.Normally, these actions occur in steps or levels,without being noticeable. In rare cases at thehighest levels of corrective action, this action maybe noticeable to the driver. If so, a DriverInformation Center (DIC) message might bedisplayed, such as Battery Saver Active or ServiceBattery Charging System. If this message isdisplayed, it is recommended that the driverreduce the electrical loads as much as possible.See DIC Warnings and Messages on page 220.183
