The old iPhone has improved battery life after upgrading to iOS 12.3.1

Apple recently released iOS 12.3.1 update to correct some bugs related to VoLTE and iMessenge. But it seems that Apple does more than that when iOS 12.3.1 also helps increase battery life on older iPhone models.

YouTuber channel iAppleBytes has performed an experiment to compare batteries between iOS 12.3.1 and iOS 12.3 on older iPhone models from 5s to 8. The results show that the iPhone 5s / 6/7 timeline improves significantly after updating to iOS 12.3.1. Specifically, iPhone 5s / 6/7 running iOS 12.3 version has battery life of 2 hours 35 minutes, 2 hours 34 minutes and 2 hours 58 minutes respectively. When running iOS 12.3.1, iPhone 5s battery life increased by 14 minutes (2 hours 49 minutes), iPhone 6 increased by 18 minutes (2 hours 52 minutes) and iPhone 7 was 18 minutes.

However, after upgrading to iOS 12.3.1 on iPhone 6s / 8, there is no difference in battery life.

Note: iAppleBytes does this test on devices with fairly new batteries and does not enable performance stabilization. First, the machines are running iOS 12.3 and tested until the battery runs out. They are then charged, updated to iOS 12.3.1 and run again. iAppleBytes uses Geekbench 4 application.

Please see the video below to better understand iAppleBytes' testing process.