configure battery power settings in Gnome
Gnome desktop does not allow users to set the values for battery critical state, Power settings will only allow users to set what action is to be taken when the battery is critical. By default it is considered critical when battery backup time is 5 minutes and it will initiate battery critical action when backup time remaining is 2 minutes. This default behavior is questionable because 2 minutes will not be sufficient for all users to find a power source and as most batteries used today are lithium-ion batteries, their life will get significantly reduced by this default behavior when drained so low so often.
Fortunately, this can be changed in configuration editor. systems using older Gnome versions such as Gnome2 desktops had a tool called Gconf-editor to change these configuration settings. Newer Gnome versions such as systems using Gnome3 desktop use a tool called dconf-editor to make changes to these configuration settings.Install this tool by using below command from terminal
sudo apt-get install dconf-editor
After installing open dconf-editor and look for following path in the left pane
In the right pane look for the fields,
and change the time values for the fields according to your preferences.Note that the time is defined in seconds.
Description for the fields and the type of value it accepts will be available at the bottom pane, when you select the fields.
Alternatively, if you want your system to consider the battery percentage instead of remaining time, uncheck the key
and modify the keys
to your preference.Now your system should take the values you defined after the next boot or restart your system for the settings to take effect immediately.