HP 421 Notebook-PC - Manual (Page 77)

Charging a battery
WARNING! Do not charge the computer battery while you are onboard aircraft.
The battery charges whenever the computer is plugged into external power through an AC adapter,
an optional power adapter, an optional expansion product, or an optional docking device.
The battery charges whether the computer is off or in use, but it charges faster when the computer is
off.
Charging may take longer if a battery is new, has been unused for 2 weeks or more, or is much
warmer or cooler than room temperature.
To prolong battery life and optimize the accuracy of battery charge displays, follow these
recommendations:
● If you are charging a new battery, charge it fully before turning on the computer.
● Charge the battery until the battery light turns off.
NOTE: If the computer is on while the battery is charging, the battery meter in the notification
area may show 100 percent charge before the battery is fully charged.
● Allow the battery to discharge below 5 percent of a full charge through normal use before
charging it.
● If the battery has been unused for one month or more, calibrate the battery instead of simply
charging it.
The battery light displays charge status:
● On: The battery is charging.
● Blinking: The battery has reached a low battery level or critical battery level and is not charging.
● Off: The battery is fully charged, in use, or not installed.
Maximizing battery discharge time
Battery discharge time varies, depending on the features you use while on battery power. Maximum
discharge time gradually shortens as the battery storage capacity naturally degrades.
Tips for maximizing battery discharge time:
● Lower the brightness on the display.
● Select the Power saver setting in Power Options.
● Remove the battery from the computer when it is not being used or charged.
● Store the battery in a cool, dry location.
Managing low battery levels
The information in this section describes the alerts and system responses set at the factory. Some
low battery alerts and system responses can be changed using Power Options in Windows Control
Panel. Preferences set using Power Options do not affect lights.
Using battery power 65