Sleep mode consumes as much as battery as when laptop is in use

Solution 1:

I could solve the issue. I will answer my own question hoping it helps anyone else facing the same problem.

The Lenovo X1 Carbon 6th gen uses a new sleeping state (Si03, Windows Modern Standby) instead of the traditional S3 sleep state. Linux does not support that new state.

The workaround presented here worked well: https://delta-xi.net/#056

Solution 2:

Execute manually:

systemctl suspend -i

In my T470s, for some reason, when closing the lid it's like is only powering the screen off, but not really suspending it, although a dmesg shows the kernel supports the correct Sx states.