I bought Dell Precision 3581 and installed Linux on it. I wanted to have deep sleep mode enabled, which, in my opinion, is a great convenience when using laptop. With my last Thinkpad I restarted system once a month using sleep mode all the time.

The problem with Dell is massive battery drainage when using sleep
mode. There are chances that my laptop survives night in a sleep mode when it is almost fully charged, but it will run out of the battery otherwise!!! 

I'm aware of some threads like:
- https://www.reddit.com/r/Dell/comments/hla8yk/how_to_enable_s3_deep_sleep_on_xps_17_9700_in/
- https://www.dell.com/community/en/conversations/xps/xps-13-9310-ubuntu-deep-sleep-missing/647f8daff4ccf8a8dee4f308?page=5
- https://www.dell.com/community/en/conversations/xps/dell-s3-sleep-mode-again/647f865bf4ccf8a8de560264
- https://askubuntu.com/questions/1398674/battery-drain-during-suspend-mode-when-lid-is-closed-20-in-8-hours
- https://www.dell.com/community/en/conversations/xps/suspend-and-hibernate-issues-on-xps-15-9500-on-linux/647f8a3ef4ccf8a8dea103d5
- https://learn.microsoft.com/en-us/windows-hardware/drivers/kernel/system-sleeping-states
- https://onlinehelp.ncr.com/Retail/Workstations/7613/HTML/Topics/UserGuide/5.%20Power%20Management/3-ACPI%20Sleep%20States%20(S0%20-%20S5).htm

I tried some BIOS 'hacks' like the ones mentioned in the first of the above links to have S3 Deep Sleep Mode enabled, however with no success. 

1) Is it possible to configure my model to force it to Deep Sleep (I found somewhere that it's not possible at all for some Dell models).

2) If so, then: How can I achieve that?