Oneplus 7Pro) After 3 years I finally replaced my back and battery!! Total $25. It was tough but really fun process to do. Took about 30minutes. The battery health was around 78%
How to show battery percentage on OnePlus 7 Pro - PhoneArena
Remove back cover
iFixit" : OnePlusOne
OnePlus One Battery Replacement - iFixit Repair Guide
OnePlus One battery repair guide | iDoc
Phone fell in water..recovering phone, data, or photos?