6 Managing power
Your computer can operate on either battery power or external power. When the computer is running on 
battery power only and an AC power source is not available to charge the battery, it is important to monitor 
and conserve the battery charge. Your computer supports an optimal power plan to manage how your 
computer uses and conserves power so that computer performance is balanced with power conservation.
Initiating Sleep and Hibernation
Windows has two power-saving states, Sleep and Hibernation.
●
Sleep—The Sleep state is automatically initiated after a period of inactivity when running on battery 
power or on external power. Your work is saved to memory, allowing you to resume your work very 
quickly. You can also initiate Sleep manually. For more information, see Manually initiating and exiting 
Sleep on page 24.
●
Hibernation—The Hibernation state is automatically initiated if the battery reaches a critical level. In the 
Hibernation state, your work is saved to a hibernation le and the computer powers down.
NOTE: You can manually initiate Hibernation. See Manually initiating and exiting Sleep on page 24
and Manually initiating and exiting Hibernation (select models only) on page 25.
CAUTION: To reduce the risk of possible audio and video degradation, loss of audio or video playback 
functionality, or loss of information, do not initiate Sleep while reading from or writing to a disc or an external 
media card.
NOTE: You cannot initiate any type of networking connection or perform any computer functions while the 
computer is in the Sleep state or in Hibernation.
Manually initiating and exiting Sleep
You can initiate Sleep in any of the following ways:
●
Close the display.
●
Select Start, click the arrow next to the Shut down button, and then click Sleep.
To exit Sleep:
●
Briey press the power button.
●
If the display is closed, open the display.
●
Press a key on the keyboard.
●
Tap the TouchPad.
When the computer exits Sleep, the power lights turn on and your work returns to the screen.
NOTE: If you have set a password to be required on wakeup, you must enter your Windows password before 
the computer will return to the screen.
24 Chapter 6   Managing power