How to calibrate a battery in an Android phone manually (without an application) 4.4.2

[VLADISLAV IZRAEL]

without a computer or a laptop

 

[Mooncatt]

Turn the phone off and charge to 100% and leave it plugged in for an additional 30-60 min (100% on the meter isn't always fully charged depending on the manufacturer programming). Then use the phone as normal until it drains completely and shuts off. Charge to 100% plus the extra time again before turning it on again.

That should do it, but it should also be noted that it's rare batteries actually need a calibration, and it's bad to fully charge or drain a Li-ion battery. It's best to keep them between 40-80% to limit extra wear and tear on the battery.