main reasons of battery drain is even you close apps but they uses ur battery and running in background unnecessary, see image and read the statement. 2nd due to huge notification enable. for e.g ; Google has huge notification which we don't need at all see image just scroll down image and check how many notification it does have. So do these settings to stop, which consume unnecessarily.
Besides above settings do some more settings to save more battery life and observe for next 1-2 days, it will give a noticeable difference
3. Device care>battery >power mode>select "optimised" and "adaptive power saving".
And then click on "app power management > And enable these 2 options. A. Adaptive battery B. Put Unused Apps to Sleep.
4. Long press on each app specially 3rd party(LIKE FACEBOOK, YOUTUBE) and rarely used apps and also ON "GOOGLE APP" as well, then click on>app info> then go to these 3 options below on by one
A. Mobile data> allow background data usage>off
B. Battery >allow background activity >off
C. Notification >disable unnecessary notifications like promotional and unnecessary reminder notifications.
5. Go to settings >apps>search "weather" >click on settings icon right side > change "auto refresh" settings as per your requirements and disable some unnecessary reminder. ( due to auto refresh it continuously consuming battery?)
6. If you use Facebook frequently then disable "auto play video" And if you are mostly uses mobile, on wifi connection then also disable "auto play videos" in YouTube.
7. Google >click on 3dot>usage and diagnostics >off this option.
7.5 hours after minimal use Most of the YouTuber used test/review phone Without sim They don't binge watch YouTube or do normal day to day use like calling, using Instagram, whatsApp whole day YouTuber have their own daily usage phone
I understand, but I really hope this improves on time with learning patterns and may be updates. Now my 3300 mah Note 8 gives me same battery as this one. and @Rohit9r do u think we will get access to s20 series beta program?