A new version of iOS 27 has begun reaching users, and some people have reported their devices heating up and losing power more quickly than before. Apple says that is not a mistake. The company’s own guidance states that reduced battery life and higher heat are normal for the first few days after installing a new update.
The headline features include Siri AI, expanded Apple Intelligence, AI photo editing, and new ways to customize Liquid Glass. The real cost, however, is hidden in the setup process itself: Apple says the phone spends its first few days after an update indexing files, downloading new assets, and updating apps to their latest versions. That background activity uses more power and produces more heat, which explains the temporary dip in battery life.
The Setup Work Behind the Drain
The company’s explanation is straightforward: right after a major software update, a device requires time to complete its background setup. The setup usually spans multiple steps.
- Indexing files and data so that system-wide search works properly
- Downloading additional assets for new features
- Updating apps to their latest versions
The increased energy use and warmth produced by that activity mean the device needs more power than usual. Apple says “battery life and thermal performance,” which measures how long the battery lasts between charges, can fall temporarily immediately after installing a new version of iOS. The company expects these problems to get better with later updates to iOS 27.
The firm adds that new features can change how a device draws power after setup ends. A feature such as Siri AI leaning more heavily on on-device processing, or expanded Apple Intelligence features running more often, increases the amount of daily computational work the phone performs compared with what it did before the update. Apple says it keeps adjusting this through follow-up updates to find a balance between new capabilities and battery life.
The Hidden Cost of Upgrading
This pattern has been with us for years now. The story cites the iOS 26 release, iOS 18, and iOS 17, each time following the same sequence of events. Users first notice their battery isn’t lasting as long, and they feel their phone getting warmer. Complaints begin to roll in at that point. Then Apple steps in to explain that the phone is still working through its setup process, and the problems resolve themselves on their own.
Given how consistently this happens every year, it is less “new problem with iOS 27” and more “the normal cost of updating.” It is generally not something worth panicking over.
What Apple Says Is Expected
The company’s support pages lay out the situation plainly: the temporary dip in battery life and thermal performance is described as expected behavior, not a sign anything is wrong. The phone is not broken; it is busy.
The setup work serves as the foundation for the new features to operate correctly. Without it, the new photo editing tools lack the information they require to function. Over the first few days following the update, the phone performs the unseen labor that enables everything else to work.
The New Devices and Their Preorders
Apple released new AirPods, Apple Watches, and iPhones alongside iOS 27. The iPhone Duo is the only device not yet open for preorder; everything else can be reserved right away.
Mashable’s General Assignments Editor Chance Townsend wrote about the launch. His beat includes tech, video games, dating apps, and digital culture, along with anything else that catches his eye. Townsend earned a Master’s in Journalism from the University of North Texas, and he describes himself as a proud orange cat father. His work has also been published in PC Mag and Mother Jones.
During his spare moments, he spends his time cooking, cherishes rest, and holds a deep fondness for Detroit sports. Should you possess guidance to share or wish to converse regarding the Lions, he may be contacted via Bluesky at @offbrandchance.bsky.social, through email at [email protected], or directly on Signal at 224-417-6628.
The History of This Pattern
The story cites the iOS 26 release, iOS 18, and iOS 17, each time following the same sequence of events. Users first notice their battery isn’t lasting as long, and they feel their phone getting warmer. Complaints begin to roll in at that point. Then Apple steps in to explain that the phone is still working through its setup process, and the problems resolve themselves on their own.
What Users Should Expect
The company has confirmed that the heat and battery drain some users report after installing iOS 27 are temporary, and said they should improve with future updates to iOS 27. The phone is simply doing more work during the transition period, so there is no lasting harm done to the device.
Take your time with the setup process. Let the phone complete its configuration over several days. As it does, the battery strain and warmth will likely subside. Should the problems continue past that point, contacting Apple Support would be a sensible next step.
Get the Notebook.
The day's best stories and every fresh verdict, in plain English, in your inbox by seven. One email a day, no more.