Most very recent laptops no longer support S3 sleep which used to be the default for a long time. On my old laptop it allowed me to just close the lid in the evening and open it again in the morning, and it would only loose a negligible amount of charge during that time.

My new laptop (Dell Inspiron 14 Plus, Alder Lake) uses s2idle by default on Linux (Fedora in my case), which depletes the battery very quickly. I tend to shut down my computer every evening now, but even when I just put my laptop in my bag for 2 hours it will have lost 10-15% when I get it out. It's not terrible and I have gotten used to using my laptop like that but there's got to be a better way right?

I know hibernation / suspend-to-disk is an option in theory, but I use secure boot (and also disk encryption), and that makes it a lot more complicated, involving compiling your own patched kernel, so no thanks.

The way sleep on modern laptops is supposed to work is apparently called S0iX but it is not used by default and I don't know if or how I could make use of it on my laptop, and a guide that is linked everywhere on 01.org now just redirects to some generic intel site.

If you have a recent laptop without S3 sleep support, how are you dealing with this? Do you just live with the poor battery life, or is there some secret to getting more power saving sleep on modern machines?

Edit for mare clarification:

• The laptop does enter s2idle correctly, it just doesn't get down to a very low power state at all and consumes ~5% an hour
• cat /sys/power/mem_sleep only returns [s2idle], no deep sleep is supported. echo deep | sudo tee /sys/power/mem_sleep doesn't work (tee: /sys/power/mem_sleep: Invalid argument)
• There's no option in the BIOS to enable other sleep modes
• I've even tried patching the ACPI table myself to enable S3 sleep and it didn't work. I have no idea if I did it correctly although according to dmesg it did seem to load my patch

Thank you all for your input but it looks like on this Dell laptop I'm stuck with horrible s2idle sleep :/