The battery warning light will come on briefly as a check, when you turn on the ignition. Then it should go out when the engine is started.

If the light does not come on when you start your vehicle, have your vehicle serviced right away. This condition may indicate your battery warning light is not functioning properly. If this light comes on while you are driving, be sure to turn off accessories such as the radio and climate control system. Have your vehicle serviced right away. The SERVICE BATTERY CHARGING SYSTEM message may also appear in the Driver Information Center. See DIC Warnings and Messages for more information.