Using external AC power
NOTE: For information on connecting to AC power, refer to the Quick Setup poster provided in the computer box.
External AC power is supplied through an approved AC adapter or an optional docking or expansion device.
WARNING! To reduce potential safety issues, use only the AC adapter provided with the computer, a replacement AC adapter provided by HP, or a compatible AC adapter purchased from HP.
Connect the computer to external AC power under any of the following conditions: 
WARNING! Do not charge the computer battery while you are onboard aircraft.
●When charging or calibrating a battery
●When installing or modifying system software
●When writing information to a CD, a DVD, or a BD (select models only)
●When running Disk Defragmenter
●When performing a backup or recovery
When you connect the computer to external AC power, the following events occur:
●The battery begins to charge.
●If the computer is turned on, the power meter icon in the notification area changes appearance. When you disconnect external AC power, the following events occur:
●The computer switches to battery power.
●The display brightness is automatically decreased to save battery life.
Using external AC power 29