iOS 27 drains iPhone batteries faster, but issue should be temporary

After installing iOS 27, some iPhone users noticed faster battery drain. The cause is background processing: search reindexing, app updates and preparing data for Siri and AI features. It usually normalizes within 24-48 hours, sometimes up to three days.

• Faster drain seen in first 24-48 hours after update
• On some devices background processing lasts two to three days
• Apple: activity does not harm battery, charge returns to normal
• Overnight charging with Wi-Fi and a phone restart help