Users may experience a temporary decrease in battery performance following the installation of iOS 26.5, released by Apple on May 11. This update introduces end-to-end encrypted RCS messaging alongside numerous bug fixes.
According to a statement from Apple in September 2025, the initial battery drain is expected as the device completes background tasks such as indexing and updating applications. The company reassured users that this effect is normal and should resolve itself.
Apple explained that increased usage of the iPhone after the update could also lead to further battery drain. Users are advised that certain features may require additional resources, potentially impacting performance and battery life.
Overall, while the update may cause some disruption, it is anticipated to be a short-lived issue, with normal performance expected to resume shortly after installation.