Users have reported faster battery drain on their iPhones following the update to iOS 27. According to Apple, this issue is temporary and stems from background processes that continue after the installation is complete.
After an update, the system performs tasks such as rebuilding system indexes, updating applications, and preparing data for Siri and other AI-based features. These operations consume energy and may cause the device to heat up, even when the screen is off.
The duration of these background activities typically lasts for one to two days, though devices with larger data volumes may require more time. Apple states that this activity does not harm the battery and that performance should normalize once the tasks are finished.
To accelerate the process, users can leave their iPhone connected to Wi-Fi and power overnight. Updating apps via the App Store and restarting the device may also help. If abnormal battery drain persists after a week, the issue is likely unrelated to the update.
