iOS 27 drains iPhone battery for a few days, Apple says it is normal
Apple attributes the shorter battery life that follows an iOS 27 install to background indexing, and says endurance returns once it ends.
Apple has released iOS 27 in its final version, and many iPhone owners report shorter battery life and warmer devices after installing it. The behaviour is expected, according to Apple’s support site: device setup continues in the background, including indexing data and files for search, downloading new elements and updating apps.
The indexing is rebuilt entirely on the device — Spotlight search, automatic sorting of the photo library, message processing. Every file, photo, document and conversation is scanned locally so that searches stay instant. Depending on how much storage is used, this work can run for several days and is demanding on the processor.
Apple says endurance returns to normal once the background tasks finish, and that the optimisations in iOS 27 usually leave slightly better battery life than before. Leaving the iPhone plugged in and connected to wifi overnight lets the indexing complete.
Advanced Siri AI features are not yet active in Europe, and the deployment of Siri AI there is expected in the coming months.
