Ubuntu – How to change critically low battery value

Slightly duplicate of How can I limit battery charging to 80% capacity?, but I won't mind. And for those that say the 80% thing is a myth, that's not what Jorge ask for; he wanted to know how to enable it, whether or not it's a myth...discuss that elsewhere.

If you don't have an option in your BIOS, it's difficult to impossible to override the hardware in your computer without the proprietary company that made your computer (HP) making a special script for you. Look for something like that, otherwise, it won't work.

Maybe look in your BIOS again. Maybe also (if you are daring enough), to update your BIOS. This is tricky, but I will not explain it here. That MIGHT allow you enable this setting. I still think that it would be in your BIOS if anywhere, check over it again. If you do update your BIOS, ensure it's a newer version, AND that it includes the "enable batter saver" option that you want (you may have to read the update notes (bleah!)).

Hope this helps! If it does, +1 me :).

Zzzach...

I found another solution for my Ubuntu 14.04 system. Maybe it works for you.

First, install laptop-mode-tools

sudo apt-get install laptop-mode-tools

Then, you must enable the auto-hibernate function. You must edit a text file:

sudo gedit /etc/laptop-mode/conf.d/auto-hibernate.conf

There, look for ENABLE_AUTO_HIBERNATION parameter and replace the 0 with a 1:

ENABLE_AUTO_HIBERNATION=1

In the same file, you also want to adjust the battery charge percentage when the computer hibernates. For example:

AUTO_HIBERNATION_BATTERY_CHARGE_PERCENT=3

Save the file and test the configuration letting your battery discharge. If it works, you must set laptop-mode-tools as default, by creating a script:

sudo touch /etc/pm/sleep.d/10-laptop-mode-tools
sudo chmod a+x /etc/pm/sleep.d/10-laptop-mode-tools
sudo gedit /etc/pm/sleep.d/10-laptop-mode-tools

Then, in gedit, copy and paste this:

case $1 in
    hibernate)
        /etc/init.d/laptop-mode stop
        ;;
    suspend)
        /etc/init.d/laptop-mode stop
        ;;
    thaw)
        /etc/init.d/laptop-mode start
        ;;
    resume)
        /etc/init.d/laptop-mode start
        ;;
    *)
        echo Something is not right.
        ;;
esac

Save the file, then restart the system and test again. I hope that it works for you.

In my opinion, it looks like something is interfering with the the gnome-power-manager. If someone else reproduces the problem, then we can report a bug.

References:

Tips for save power by Penalvch https://help.ubuntu.com/community/PowerManagement/ReducedPower#Using_less_power_with_laptop-mode-tools

Re: Getting Ubuntu to automatically suspend on battery low (command-line) by Isamu715 http://ubuntuforums.org/showthread.php?t=2092327&p=12394451#post12394451