I would like my laptop to hibernate itself when the battery level is 10% to be sure it has enough power to complete the operation properly. Actually if I don't pay attention my laptop informs me it will hibernate when it's too late, so instead it brutally shuts down. This kills lithium batteries and is not acceptable.
You can also do this from a terminal with:
Looks like Gnome moved the settings. Critically low battery is now handled by UPower. Instead of using gsettings, you should now edit the file
By the way, if you read the UPower.conf file, upower used to (in v 0.99.1) only suggest using percentages in order to work around broken firmware. The default was
However, it looks like upower now (v 0.99.4) is defaulting to percentages and has a cryptic message about the reasoning. I don't know which is best, but here's how to use time remaining for your battery policy, if you so desire.