BATTERY / DC OPERATION 149 2. Press F3 (Battery). The level icon appears at the bottom of the display. BatteryF 3 Fully charged 50% to 25% 75% to 50% Less than 25% Note Regardless of battery check, the GSP-830 shows the icon for 5 seconds every 30 minutes. Battery maintenance To prolong the battery life, take out the batteries when they are not in use for more than one month. Parameter Usage time 3 hours (typical) Charge time 3 hours (typical) Check battery installation status Panel operation 1. Press the System key. System 2. Press F6 (More). More...F 6 3. Press F4 (System Config On). The configuration appears. System ConfigOn OffF 4 4. The Battery sign shows the installation status, installed (checked) or not installed (unchecked). Installed Not installed DC Operation Panel operation Connect the DC power cable to the rear panel input connector. Specification 12V, 40W max, 2.1mm plug Battery charging When the DC power is in use, the batteries are also charged. Note DC power cable (with a lighter plug for automobile usage) is available as an optional item, GTL-401 (page174).