Clear all used apps before charging and/or put the phone in airplane mode if possible. That way you'll get "rapid charging" (around 2 hrs and 40 mins, from 0 - to 100%).

For battery mileage, make sure as many apps as possible are battery optimized, especially Android System. Turn off it's background activity ("Apps background is limited when not in use"). Also deny background data usage for apps for which you think background data access is unnecessary. The same goes for access to location services.

Allow auto-sync only for important apps like Gmail and Contacts and possibly your other chosen apps. Keep Data Saver turned on. Disable wifi scanning if not necessary.

Uninstall or disable any apps that are useless to you via the conventional method or via adb, if necessary (I safely uninstalled/disabled a total of 23 system apps and a few more 3rd party bloatware ones).

Cut down Window and Transition animation scales and Animator duration scale to .5x in Developer Options. This will speed up operation of your phone and overall power wastage on animations will be reduced. Keep notifications on only for the apps/system apps that you need.

Read somewhere that by running the battery down to shut off and recharging it to 100% in off mode before restarting it in fully charged state - before unplugging it, will "calibrate" your battery. Dunno how far that is true but I've done it the prescribed 3 times - just in case.

Wipe the cache partition via recovery mode after a big ass, major update.

Use Naptime like me! 

I have never cleared my cache partition since day one. Haven't had any battery drain issue. Hmm...maybe I should do it since charging my phone takes like 4 hours now to 100%.

Whoa...that is SLOW!

I don't think your slow charge is due to an uncleared cache partition. The impact of residual firmware cannot be that bad.

Must be something else...like maybe data or wifi left on or uncleared apps?

I never turn off my Wifi. It is always on. Data will be off when I am disconnected from my home WiFi (using Automate). If need constantly micro manage your phone like this, then that phone tak boleh pakai.

Sigh! Why still cannot break @azhar75  18hrs SoT record ?😀

Don't need to do that bro. Even tea lady have iphone. So it's nothing to brag about.

I have never cleared my cache partition since day one. Haven't had any battery drain issue. Hmm...maybe I should do it since charging my phone takes like 4 hours now to 100%.

In-human + micro management = red eye sickness... LOL...

Is there any chance of M1 breaking the LeMoto P2 20hrs SOT ?🤔

If need constantly micro manage your phone like this, then that phone tak boleh pakai.

Sigh! Why still cannot break @azhar75  18hrs SoT record ?😀

Big fat, NO! LeMoto P2 is having 5,100 mAh... M1 only 100 mAh less... But Super AMOLED & smaller screen size leads to longer SoT... LeMoto P2's 3G/4G connectivity also stronger and more stable than M1 especially the Wi-Fi...Plus, Snap625 is the King of Power Efficiency...

Nothing to be surprised...

Big fat, NO! LeMoto P2 is having 5,100 mAh... M1 only 100 mAh less... But Super AMOLED & smaller screen size leads to longer SoT... LeMoto P2's 3G/4G connectivity also stronger and more stable than M1 especially the Wi-Fi...Plus, Snap625 is the King of Power Efficiency...

Couple of things that struck me

1 - The SD845 seems to be a very power-efficient chipset. Had they put that into my Note 9 maybe I wouldn't have sold it off so soon
2 - Imagine if the OnePlus 6 had a 4000mAh battery!

After you mentioned so many good points of P2,
should I sell my M1 and get a LeMoto P2 ? 

I guess, this is my best record

Yes. I was reviewing the ZenFone 5Z a few weeks ago and quite amazed with the energy performance of the 5Z. Ever since the released of Snap625, the Qualcomm Team has found the secret recipe to power efficient chipset. Thanks to their mistakes when releasing the Snsp61X series a few years ago when they did not familiar with the algorithm of ARM big.LITTLE architecture...

Please don't leave the balance to be lower than 20% too frequently. It'll deteriorate the ions in the battery cells faster than it should be...

Yup, am thinking now of ditching my plans to get a Poco and go for either a used 1+6 or wait for 1+6 prices to drop below 2k

Have you tried any 1+ devices bro?

Read somewhere that by running the battery down to shut down and recharging it to 100% in off mode before restarting it in fully charged state - before unplugging it, will "calibrate" your battery. Dunno how far that is true but I've done it the prescribed 3 times - just in case
So which one of the above statement is true ?

Why change of mind of getting POCO ? I saw many good reviews about this phone.