Windows Power States

I've recently received a new laptop from my employer, a pretty nice Lenovo machine. After the first days using it I realised there was something odd. When waking it up in the morning after having put it to sleep in the late evening, the battery level had quite dropped, one day the laptop was hot as if it had not really entered into sleep. I suspended it several times and it seemed to get into sleep OK, so maybe it was more a thing of waking up from the suspended state for some reason. The windows event log seemed to show it entering into suspension and going mute, but after several hours there would be entries in the log, so yes, something was waking it up.

Doing some searches for Windows 10 Sleep/Stand by issues I thought I've found what was happening. Windows 10 comes with a new Sleep mode, Modern Standby (S0 Low-power Idle) that, if your hardware supports it, is used rather than the previous S3 mode (my previous Lenovo work laptop, dating back to 2017 did not support Modern standby). This Modern Standby thing comes with 2 modes: Connected and Disconnected.

Devices that support Modern Standby can connect or disconnect from Wi-Fi or a wireless local area network while in standby.

- Connected Modern Standby will allow the device to remain connected to Wi-Fi while in standby. It will be able to receive and process notifications about new email messages, incoming calls. This is convenient, but makes the device drain the battery power faster.
- Disconnected Modern Standby allows longer battery life, but the device won't notify you about new events.

Resuming from "traditional" sleep mode has always been almost immediate, so for most users I don't see what's the use of Connected Modern Standby mode in a laptop. Receiving notifications while it's in standby and hence waking up?! I guess after that it will go back to sleep following the inactivity rules on your system, but if you're receiving notifications pretty often this will be a battery draining mess. I was thinking it could be something like that what was happening to my laptop, so I wanted to turn off this behaviour.

First I confirmed with powercfg -a that my new laptop is using this Connected Modern Standby thing.

As you can see, the traditional S3 mode is not supported by my Hardware. It seems Hardware can not support both Sleep states (read here

Modern Standby is only available on some SoC systems. When it's supported, the system does not support S1-S3.

So the solution is switching from Connected Modern Standby to Disonnected Modern Standby. For that you just have to go to Settings -> System -> Power & Sleep and in the Network connection settions select Always

Unfortunately I've faced once again the problem of finding my laptop hot and with a very low battery level in the morning, even when using this Disconnected mode... Checking the event log it seems the laptop got into sleep and woke up immediatelly, don't know why, so I've had to resort so far to the Hibernate mode to avoid problems. Anyway, it's been interesting to learn about the current types of Power States in modern Windows/modern Hardware.