Configuring Power Management in Ubuntu

Advanced Configuration and Power Interface (ACPI) enables workstations and servers to automatically turn off when instructed to shut down. Most often used by Linux mobile users, ACPI can help extend battery sessions through the use of intelligent storage-cell circuitry, CPU throttling (similar to, but not the same as safety thermal throttling incorporated by Intel in Pentium III and IV CPUs), and control of displays and hard drives.

Most PCs support ACPI via the BIOS and hardware. ACPI support is configured, enabled, and then incorporated in the Linux kernel.

ACPI information is constantly available through the acpi command, which looks like this:

$ acpi -V     Battery 1: charged, 100%     Thermal 1: ok, 47.0 degrees C     AC Adapter  1: on-line 

This example provides information such as battery charge status, percentage of charge, as well as current system temperature and status of the AC adapter.