[rudra]

Thanks for the nice tip. Though I kinda knew about it already. Here is what I know,

calibration :
it is done when battery percentage sensing goes off with time.It is like setting up max and min voltage levels as 100% and 0% charge level and subdivide the range. Now i don't know how or if they account for the non-uniformity of energy-output/input of every percent charge level. May be they just dont go to all that complexity and linearly divide charge level scale according to voltage.

Battery charging :
these mobile batteries have a no of recharge cycles that they can take and function ok. so for longevity one should keep charge level between 40 to 65. That will afford you more cycles. the wider you go or closer you approach 0 to 100, the faster you expend your cycles.

also charging slower (less amp) and cooler will aford longer life too.
playing heavy games or doing things that engages near max resources means using higher amp, which means more battery heat. bad for its life.

I am very fastidious about what runs in my mobile.

[deanhills]

also charging slower (less amp) and cooler will aford longer life too.

So would you then say that charging a phone through a USB port on a computer is more ideal than a USB through a wall charger?

[rudra]

@deanhills
yes. thats what i notice. usb 1 and 2 send 500 mA, 3 does 900 mA and charging port ver. 3 does 1500 mA. So yes.

i like to allow less mAmp even when the onboard regulator allows 1500 or more. I do this by reporting fake max voltage rating in script.

I also noticed that charge slow and long and you will get some more time. charge faster and it goes down faster too. But that may just be an illusion to my confused mind. cause even though i have noticed it for my phones, my sample size is too little and i didn't design any proper test for my hypothesis.

[humanpuff69]

the micro usb port in the phone is probably worn out . Maybe replacing the botto, board that contain the port will fix it . bad usb port is common issue espescially with older micro usb

[adgod]

I have a Redmi Note 4 and had the same issue. It was a excellent condition as well. Not a scratch, dropped only once. It randomly stopped charging. I did clean the port and it worked fine untill sometime the issue arises again. Now I have to plug in an angle and rest some tension on the wire to keep it charging. Didn't find any fix after that.

[rudra]

thanks for taking time to contribute on such an old topic. yes, i still have that phone too. though i might soon sell it on cashify. they are still paying well for this model. i have it in nice condition too.
That trouble is still there. You might be right. may be my using a non mi charger might have bent or damaged the port. but this is quite unexplainable to me as to how can this be so random. sometimes you just do a switch off n on for the charger and it starts working again ... weird really. Also why would i have to pull it out n then push in to make it work. jimmying never works. why ? weird