iPhone battery calibration

This is the 3rd time battery calibration has fixed a 3rd party iFixIt battery for me with iPhone SE 1st generation (2017).

Unexpectedly and suddenly iOS reported dropped battery % (to 80-60-20% etc) with the previous usage pattern (i.e. screen off, no iOS updates, no extra app usage in poor mobile cell coverage, no GPS etc).

coconutBattery also suddenly dropped to ~50-60% "Health" (screenshot attached).

Confusingly iOS 15.7.9-15.8.2 > Settings > Battery still reported "Battery max capacity 100%". iPad OS 17.4.1 does not have that info and maybe iOS does not properly read 3rd party battery?

Anyways, this iFixIt hint fixed it:

* Charge to 100%, and keep charging it for at least two more hours.

* Use the device until it shuts off due to low battery [this took considerable time even when iOS reported 1% battery and at some point I put screen brightness to the max and used apps and map apps so the GPS chip would consume the battery more. I guess iOS did not properly report the correct battery capacity].

* Charge it uninterrupted to 100%.

After that the iOS battery % behaved as expected and also coconutBattery "Health" jumped back to +100%.

Some sources say that battery calibration is no longer needed but this experience suggets otherwise at lest with such 3rd party batteries.