Apple will recalibrate iPhone 11 batteries to fix performance and capacity issues - The Verge
How to Calibrate an iPhone
How To Calibrate iPhone Battery
High Quality iPhone 4S Battery - 1430 mAh | iParts4U
IPhone 11]iOS 14.5 can re-calibrate the iPhone battery life status. If an abnormality is found, Apple can replace the battery for free | Apple products - Archyde
Why you shouldn't calibrate the battery in your iPhone, iPad, or iPod