Apple iOS 11 is packed full of features (including many secret ones), but following reports of several bugs my Upgrade Guide advised iPhone users in particular should hold off updating. This now looks a wise move because iOS 11 is causing problems…
A new report from mobile security firm Wander a exposes the issue: iOS 11 a battery killer.
Cutting through the usual subjective battery life complaints iPhone and iPad users often post online after an iOS update, Wandera found concrete evidence of serious degradation. It did this by monitoring a "subset of 50,000 moderate to heavy iPhone and iPad users” on its networks running iOS 11 and iOS 10.
The result: battery life for iOS 11 upgraders is decaying over twice as fast as those running iOS 10.
Breaking this down, Wandera reports iPhones running iOS 10 can be used for 240 minutes on average before the battery dies. Meanwhile iPhones running iOS 11 last just 96 minutes on average - a massive 60% decline.
"In other words, the decay rate for iOS 10 is 0.006958 percent per second and for iOS 11 it’s 0.01739 percent per second”, Wandera’s report explains.
Wandera attributes some of this disparity to Spotlight re-indexing on iOS 11 as well as upgraders wanting to try out all the new features, but that doesn’t account for the overall size of the drop. As such it suggests badly affected users mitigate the issues until Apple finds a fix by limiting the number of apps which can run in the background (Settings > General > Background App Refresh) and access your location (Settings > Privacy > Location Services).
But realising the limited potential of these options, Wandera accepts: "low power mode may be your best option until Apple pushes out new updates that will hopefully address excessive battery drain.”
More drastic options have seen some iOS 11 upgraders achieve improvements by factory resetting their iPhones, but this comes with a catch. You cannot factory reset and restore from a previous backup, you must setup as a brand new device. This means losing all your apps, data and settings - and it still doesn’t work for everyone.
Interestingly I’ve seen no reports of the recently released iPhone 8 and iPhone 8 Plus being troubled. So this appears to be hitting upgraders only.
Looking at the big picture, iOS 11 continues Apple’s mixed track record with major upgrades and bug fixes have been quickly issued for most generational updates since iOS 8. Why? Because the more an upgrade changes, the more chance it has of breaking something.
So if you have upgraded to iOS 11 and have had no ill-effects, congratulations. But if you are affected or you have yet to upgrade, I suspect iOS 11.1 or iOS 11.0.1 can’t arrive soon enough…