GoKawiiliOS 27 update causes temporary battery drain on iPhones, Apple says
Apple's iOS 27 rollout is causing some iPhone users to see faster-than-normal battery drain in the days following installation. The company attributes this to background processes like search-index rebuilding, app refreshes, and data prep for Siri and AI features, which typically resolve within one to three days. Users with large photo libraries or heavy AI usage may see the effect last longer.