iOS 11.3 Beta 2 Released, Includes Battery Health Information & Controls « iOS & iPhone :: Gadget Hacks
How to View Battery Health and Disable Performance Throttling in iOS 11.3
11 pro max with iOS 14 beta 5, is the battery life normal? (From 85% to 21%); Half day used WiFi and half day used LTE with Bluetooth always on : r/iOSBeta
iOS 11.3: How to check if your iPhone is being slowed down - CNET
About recalibration of battery health reporting in iOS 14.5 - Apple Support