Every year when Apple releases a new iOS version, most users end up having the same complaint: the previous version offered better performance and battery life. Apple addressed the performance issues head-on with iOS 12 last year as it brought about major performance improvements even on older iPhones, though that performance came at the cost of slightly worse battery life.

In terms of battery life though, which iOS version is the best? Which one will ensure that your iPhone runs the longest period of time possible on a single charge? YouTuber iAppleBytes has compared the battery life of iOS 10.3.3, iOS 11.4.1, iOS 12.2, and iOS 12.3 beta 1 across a range of devices. The results were pretty surprising and shocking at the same time.

Running the Geekbench battery test, the iPhone 6s running iOS 12.3 beta 1 lasted for 3 hours 19 minutes. In the same test, the iPhone 6s lasted an additional 9 minutes (3h28m) when running iOS 12.2. On iOS 11.4.1, the battery life was slightly worse and the iPhone 6s lasted 3 hours and 23 minutes. However, the results while running iOS 10.3.3 were simply outstanding, with the iPhone 6s lasting for 5 hours and 40 minutes — that’s over two hours more than iOS 11 – iOS 12!

The results were definitely not a fluke as the iPhone 6s running iOS 10.3.3 again lasted the longest while playing back a 15-hour video on YouTube. While the iPhone 6s running iOS 11.4 and iOS 12.2 last for around 10 hours and 30 minutes, the iPhone 6s unit running iOS 10.3.3 managed to last for 11 hours and 41 minutes. That’s over an hour more when compared to iOS 11 – iOS 12.2 and 100+ minutes when compared to iOS 12.3 beta 1.

Our Take

Apple might have brought about noticeable performance improvements with iOS 12 but that seems to have definitely come at a cost. Surprisingly, the battery life difference between iOS 11 and iOS 12 is not that massive but the decrease in battery life between iOS 10 and iOS 11 is massive. Apple really needs to work on optimizing its software more for older devices to ensure that their battery life and performance does not tank so badly after a major OS update.

It is kind of ironic to see iOS 10.3.3 beating iOS 11 and iOS 12 in a battery life comparison test as Apple claims battery life improvements with both iOS 11 and iOS 12.

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