A new iOS release typically also brings about a slight hit to battery life. This is something we saw with the release of iOS 12 last year as well as all that performance improvement came at the slight expense of battery life, particularly on older iPhones.
Apple does not promise any major battery life improvements with iOS 13. It only promises faster app launch times apart from a plethora of features that it brings to the table. What this should mean is that an iPhone running iOS 13 should offer almost the same battery life as it did while running iOS 12.4.
YouTuber iAppleBytes decided to test this and conducted a battery test on iOS 13 Beta 7 to see how it holds up compared to iOS 12.4 on older iPhones like the iPhone 6s, iPhone 7, and iPhone 8. While beta builds carry the beta tag for a reason, Apple has so far released 7 beta builds of iOS 13 which means it has had more than enough time to optimize the OS for performance and battery life.
For the test, iAppleBytes first ran the Geekbench battery test on iPhone 6s, iPhone 7, and iPhone 8 running iOS 12.4 and then repeated the same test after updating them to iOS 13 beta 7.
The iPhone 6s lasted 3 hours 17 minutes in Geekbench’s battery test while running iOS 12.4. After updating to iOS 13 beta 7, its runtime remained almost the same at 3 hours 18 minutes. The iPhone 7 managed to last 3 hours 35 minutes in the battery test while on iOS 12.4. On iOS 13 beta 7, its runtime was 3 hours and 30 minutes. The iPhone 8 lasted for 3 hours 25 minutes while running iOS 12.4 as well as iOS 13 beta 7.
While not exactly scientific, all three iPhones performed the same in the battery test while running iOS 12.4 and iOS 13 beta 7. I won’t be too optimistic about the final public build of iOS 13 bringing any notable improvements over these results.
Given the sheer number of features that iOS 13 brings to the table, it is commendable to see that it does not bring about a drop in performance or battery life.