On older Linux OS versions, the system used to automatically suspend on low battery. Then this was managed by gsettings using

`gsettings set org.gnome.settings-daemon.plugins.power critical-battery-action 'suspend'`

But there have been some breaking changes (for the good) that has taken all of this out of any obvious control of the user. If you open _/etc/UPower/UPower.conf , _you will see that the only option _CriticalPowerAction=HybridSleep _. So Hybrid-Sleep/Hibernate/Shutdown are the only options on low power. Testing out hybrid-sleep (using sudo /usr/lib/systemd/systemd-sleep hybrid-sleep) does not do anything… which is unsurprising.

So what you need to do is switch HybridSleep to actually suspend. The way to do it is

Create a /etc/systemd/sleep.conf

<code>[Sleep]
# And finally settings for hybrid-sleep -action
HybridSleepMode=suspend platform
HybridSleepState=mem


# Setting for suspend -action
SuspendState=mem disk #freeze
SuspendMode=suspend
</code>

verify by running sudo /usr/lib/systemd/systemd-sleep hybrid-sleep