iOS 15.4 battery life tested: Shorter battery life on iPhone 12/13, but extended iPhone 6s battery life!

Few weeks ago Apple has launched the iOS 15.4 public release to most iPhones on the market. However, some has reported reduced in battery life where its battery can only last for half a day, and iPhone 11 has recorded loss of 80% battery level in just 24 hours, with only 2 hours of screen time.

In a comparison with iPhone 13, 12, 11 and XR, the iPhone 13 sustained up to 8.26 hours, which is shorter by 8 minutes compared to iOS 15.3.1. iPhone 12 battery life has dropped by 22 minutes compared to 15.3.1. iPhone 11 remains similar before and after update.

However, this update isn’t entirely bad for iPhone 6s, 7 and 8. All three models seen improved battery life with this update by extending up to 20 to 30 minutes. The iPhone SE 2020 also seen longer battery life by 30 minutes with this update.