After upgrading to kernel 4.13, the battery of my laptop started to drain while powered off (about 30% in one day). This didn't happen if I booted the laptop from kernel 4.12 or Windows 8.1, so the problem is clearly related to the new kernel version.
I used to have a similar issue due to the wake-on-lan (WoL). However, that was solved long ago by permanently disabling the WoL. I can easily verify with
ethtool that the WoL is still disabled.
Could it be that the WoL is re-enabled when I shutdown the laptop from poweroff menu? Indeed, if I enforce a hard shutdown (i.e., by keeping the power button pressed) then I observe no battery drain. However, I don't have enough skills to verify this hypothesis.
It would be awesome if someone could help me debug this problem.