156 LIGHTINGBattery Load ManagementThe vehicle has Electric PowerManagement (EPM) that estimates thebattery's temperature and state ofcharge. It then adjusts the voltage forbest performance and extended life ofthe battery.When the battery's state of charge islow, the voltage is raised slightly toquickly bring the charge back up.When the state of charge is high, thevoltage is lowered slightly to preventovercharging. If the vehicle has avoltmeter gauge or a voltage displayon the Driver Information Center(DIC), you may see the voltage moveup or down. This is normal. If there isa problem, an alert will be displayed.The battery can be discharged at idleif the electrical loads are very high.This is true for all vehicles. This isbecause the generator (alternator)may not be spinning fast enough atidle to produce all of the powerneeded for very high electrical loads.A high electrical load occurs whenseveral of the following are on, suchas: headlamps, high beams, rearwindow defogger, climate control fanat high speed, heated seats, enginecooling fans, trailer loads, and loadsplugged into accessory power outlets.EPM works to prevent excessivedischarge of the battery. It does thisby balancing the generator's outputand the vehicle's electrical needs.It can increase engine idle speed togenerate more power wheneverneeded. It can temporarily reduce thepower demands of some accessories.Normally, these actions occur in stepsor levels, without being noticeable. Inrare cases at the highest levels ofcorrective action, this action may benoticeable to the driver. If so, a DICmessage might be displayed and it isrecommended that the driver reducethe electrical loads as much aspossible.Battery Power ProtectionThe battery saver feature is designedto protect the vehicle's battery.If some interior lamps are left on andthe ignition is turned off, the batteryrundown protection systemautomatically turns the lamp off aftersome time.Exterior Lighting BatterySaverThe exterior lamps turn off about10 minutes after the ignition is turnedoff, if the parking lamps or headlampshave been manually left on. Thisprotects against draining the battery.To restart the 10-minute timer, turnthe exterior lamp control to the offposition and then back to the parkinglamp or headlamp position.To keep the lamps on for more than10 minutes, the ignition must be on orin ACC/ACCESSORY.
