Configuring Power Management

KDE 4 lets you adjust a number of power management settings: for example, when to trigger notifications or warnings, which power profile to use when running on battery, what to do when closing the laptop lid or pressing the power or sleep button.

Access the configuration options from the main menu by selecting Configure Desktop+Advanced+Power Management. Conversely, click the battery monitor icon in the panel and click select More.

Figure 9.2. Power Management Settings

Power Management Settings

To get an overview of your system's power management abilities like supported suspend methods or CPU policies, click the Capabilities category on the left.

In the following, find some examples of which aspects can be changed in the General Settings category and how to configure power management profiles.

Procedure 9.1. Configuring General Settings

To access the following options, click the General Settings entry on the left side of the power management configuration dialog.

  1. In the Settings and Profiles group, decide if the screen should be locked after a suspend action, so that the user needs to type in his password when the machine resumes after a suspend.

  2. Configure which notifications or warnings you want to receive for certain events (like low battery status), or if you want suspend actions to be executed immediately or only after a certain time interval.

  3. In Profile Assignment, decide which power profiles should be applied by default when the system is running on AC power, on battery, or when the battery is low or at warning level.

  4. Click Advanced Battery Settings if you want to fine-tune the battery levels that are regarded as low or critical or to define which action should be taken at a critical battery level.

  5. For detailed information about the available options, click Help.

  6. If all options are set according to your wishes, click Apply.

Procedure 9.2. Configuring Power Management Profiles

Apart from the general settings, you can adjust the default power management profiles or add new profiles in the Edit Profiles category. The list at the left show the available profiles.

  1. Select one of the profiles in the list to view or change the specific settings for that profile:

    1. In the Actions group, decide which actions are taken when the lid of the laptop is closed or the Power or Sleep button is pressed.

    2. In the Screen group, configure how much the screen is dimmed and after how many minutes the display is turned off automatically.

    3. Click CPU and System to view or change which CPU to turn off (if supported by your machine) or to set the CPU frequency scaling policy for that profile.

  2. Use the icons at the bottom of the list of profiles if you want to add, delete, import or export power management profiles.

  3. If all options are set according to your wishes, click Apply.