GPSMAP 78 Series Owner’s Manual 33Customizing Your DeviceAltimeter Accuracy: ± 10 ft.(± 3 m)*Resolution: 1 ft. (.3 m)Range: from -2,000 ft.to 30,000 ft.(from -610 to 9144 m)*Subject to proper usercalibration.Compass Accuracy: ± 2 degrees(± 5 degrees in extremeNorthern and Southernlatitudes)*Resolution: 1 degree*Subject to proper usercalibration.Maximizing Battery LifeUsing the Battery Save OptionUse the battery save option to savebattery power and prolong battery life.From the main menu, select Setup >Display > Battery Save > On.Decreasing the BacklightExtensive use of screen backlightingcan significantly reduce battery life.You can adjust the backlight brightnessand decrease the backlight timeout tomaximize battery power.1 Quickly press to open thebacklight status page.2 Use the rocker to adjust thebrightness.adjusting the Backlight TimeoutFrom the main menu, select Setup >Display > Backlight Timeout.about the BatterieswarninGSee the Important Safety and ProductInformation guide in the product box forproduct warnings and other importantinformation.The temperature rating for the devicemay exceed the usable range of somebatteries. Alkaline batteries can ruptureat high temperatures. Alkaline batterieslose a significant amount of their capacityas temperature decreases. Use lithium