iPhone 16 Battery Drains Fast After Latest iOS Update

I purchased my iPhone 16 on December 19, 2025, and after the most recent update, I started experiencing a serious battery and charging issue. With normal use, the device can’t make it through the day—its battery drains very quickly, and the problem has reached a level that makes the phone difficult to use.

Because of this issue, I took the phone to an authorized service center and requested a battery test. The test results showed that my battery health is normal, but despite that, the battery continues to drain rapidly and there has been no improvement in performance.

I am requesting that this post-update battery drain issue be investigated in detail, including a software-level review if necessary, and that a permanent fix be provided.