iOS 13.3 improves battery life and performance on older iPhones
Battery drain & iOS 13.3 | MacRumors Forums
iOS 13 on the iPhone 6S and SE: New software runs fine on a phone that's still fast | Ars Technica
iOS 13 Battery Life Drain Vs iOS 12.4.1 Compared [Video] | Redmond Pie
iOS 16.2 Battery Drain Issue? Poor Battery Life? How To Fix!
Battery drain overnight ios 13.3.1 iPhone 11 pro max issue : r/ios
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Help] WiFi idle energy battery drain. Woke up and phone was at 50% from 100%. I've had battery drain issues since updating to iOS 13.3 from 12.4 : r/jailbreak
SOLVED] iPhone Battery Draining Fast after iOS 16/15/14 Update