My OS is Fedora 35 Beta with the 5.14 Linux kernel. This version gave me “everything works out of the gate” status. Aside from installing KDE-DE (not a gnome fan), I didn’t have to download anything else for this system to “just work.” As far as tweaking the battery, I’ve done several things so far. Just note that I haven’t measured any of the changes I’ve made so I don’t have hard results. My test tonight is really the first one I’ve done.
But back to what tweaks I’ve made. I installed TLP so I can manage power settings while on battery mostly but it allows for optimization while plugged in. You basically edit the configuration file enabling features you want and the values of those features. While on battery, anything and everywhere I could, I ensured it was in powersave and/or powersupersave modes. Ill post a cat tlp.conf of my system so you can get an idea of what I did.
The other thing I did was change my mem_sleep parameter from s2idle to deep state. I was having issues initially trying to do this until I figured out that you have to be completely in root in order for the changes to go into effect. You can’t even simply type sudo in front of the command as it will still deny permission.
Each OS might be a little different in how you implement this change but since you and I are running Fedora, I’ll cover what I did. I ran the “echo deep > /sys/power/mem_sleep” terminal command in superuser mode (remember). I ran cat on the file to double check the change and it did change. The next thing I did was change the grub.conf file so it would always be enabled on startup and forego having to repeat all these steps every time. You do this by typing mem_sleep_default=deep on the GRUB_CMDLINE_LINUX string. Make sure it’s within the quotations and at the end of the string. Lastly, you just need to rebuild the GRUB by typing sudo grub2-mkconfig -o /boot/efi/EFI/fedora/grub.cfg
That should do it. Just reboot the system and double check the file with cat again to see if the changes took effect. I’ll post some screenshots tomorrow for a visual guide.
I hope this helps out.
UPDATE I had to go onto my FW to reference something so it killed my overnight test (I’ll restart). But, to give you an idea of the power savings I have now: I went from 100% full battery to 97% in just over 2.5 hours of time. A loss of 3%. I normally sleep 6-8 hours so we are roughly talking anywhere between 10-12% battery charge degradation overnight. I’ll take it. 