Thats normal behavior of xfce4-power-manager
, if you get no response after you run this command the process is started. You can check it with this command:
ps aux | awk -v s="xfce4-power-manager" 'NR>1 && $11~s'
the output should be something like this:
username 8223 0.0 0.8 33344 4148 ? Ssl 10:23 0:00 xfce4-power-manager
(Source)
If you want to change the settings of the xfce4-power-manager you have to run:
xfce4-power-manager-settings
or
xfce4-power-manager --customize
But its not normal that xfce4-power-manager
does not autostart...
To autostart xfce4-power-manager this should help: Lubuntu: How do I autostart xfce4 power manager?
This could be also helpfull : xfce4-power-manager is not running by default with Lubuntu 13.10 (Bug)