Advances in power management and battery technology are increasing the time that a laptop can be disconnected from AC power. Current batteries can last up to 10 hours or more without recharging. Configuring laptop power settings to better manage power usage is important to ensure that the battery is used efficiently.
Power management controls the flow of electricity to the components of a computer. There are two methods of power management:
- Advanced Power Management (APM)
- Advanced Configuration and Power Interface (ACPI)
APM is an earlier version of power management. With APM, the BIOS controls the settings for power management.
ACPI has replaced APM. ACPI standards, as shown in the figure, create a bridge between the hardware and OS and allow technicians to create power management schemes to get the best performance from a laptop. The ACPI standards are applicable to most computers, but they are particularly important when managing power in laptops.