2005 Cadillac CTS Owner's Manual - Page 192

Turn off all unnecessary accessories to allow the battery to recharge. The normal battery voltage range is 11.5 to 15.5 volts. You can monitor battery voltage on the DIC by pressing the INFO button until you find BATTERY VOLTS. Battery Voltage Low This message will appear when the electrical system is charging less than 10 volts or if the battery has been drained. If this message appears immediately after starting the engine, it is possible that the generator can still recharge the battery. The battery should recharge while driving but may take a few hours to do so. Consider using an auxiliary charger (be sure to follow the manufacturer's instructions) to boost the battery after returning home or to a final destination. If this message appears while driving or after starting your vehicle and stays on, have it checked by your GM dealer immediately to determine the cause of this problem. To help the generator recharge the battery quickly, you can reduce the load on the electrical system by turning off the accessories. The normal battery voltage range is 11.5 to 15.5 volts. You can monitor battery voltage on the DIC by pressing the INFO button until you find BATTERY VOLTS. Battery Voltage High This message indicates that the electrical charging system is overcharging the battery. When the system detects that the battery voltage is above approximately 16 volts, this message will be displayed. To reduce the charging overload, use the vehicle's accessories. Turn on the exterior lamps and radio, set the climate control on AUTO and the fan speed on the highest setting, and turn the rear window defogger on. The normal battery voltage range is 11.5 to 15.5 volts when the engine is running. You can monitor battery voltage on the DIC by pressing the INFO button until you find BATTERY VOLTS. 3-66