Public bug reported: To use laptop-mode, one needs to enable it in /etc/default/acpi-support. Then, when one unplugs the AC, laptop-mode gets enabled properly.
However, if the laptop boots up unplugged, laptop-mode never gets started. This is fixed on my Sony SZ3 laptop by entering this command: sudo update-rc.d laptop-mode multiuser ** Affects: Ubuntu Importance: Undecided Status: Unconfirmed -- Laptop-mode is not started at boot when laptop is unplugged https://launchpad.net/bugs/80979 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs