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 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 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, 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 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.
Battery Power ProtectionCharging System Light
This light will come on briefly when the ignition is turned on, and the engine
is not running, as a check to show it is working.
It should go out when the engine is started. If it stays on, or comes on while
driving, there may be a problem with the electrical charging system. Have it checked ...
Vehicle Identification Number (VIN)
This legal identifier is in the front corner of the instrument panel, on the
left side of the vehicle. It can be seen through the windshield from outside. The
VIN also appears on the Vehicle Certification and Service Parts labels and certificates
of title and registration.
Engine Identifi ...
Battery Charging
Special Tools
EL 50313 Battery Tester
For equivalent regional tools, refer to Special Tools.
Diagnostic Aids
For best results, use an automatic taper-rate battery charger with a
voltage capability of 16 V.
The charging area should be well ventilated.
Do not charge a bat ...