Battery Drain on iOS 26 and iOS 26.0.1.

Good morning everyone,

I would like to report a VERY SERIOUS problem with the battery and performance.

I have a NEW iPhone 15 with 100% battery capacity and only 22 cycles (which I did myself; when it arrived, it was at 0).

However, after updating to iOS 26 (and even with iOS 26.0.1, the situation remains the same), I continue to have VERY SERIOUS problems with the battery life of my NEW phone.

Today, I was busy all day and did not use my phone from 8 a.m. to 4 p.m., yet it still dropped from 90% to 45% WITHOUT DOING ANYTHING. No apps were open, the “Refresh apps in background” option was not enabled, the screen was set to turn off automatically after 30 seconds, and automatic brightness was enabled. So it's definitely not the phone's fault because it's BRAND NEW with a 100% ORIGINAL battery, nor is it the settings because it was in PERMANENT POWER SAVING mode. So the fault lies solely with iOS. There are no excuses.

I am writing this message to urge Apple to resolve this issue as soon as possible because, from what I have read on X, I am not the only one.

Has anyone else had this problem?

Thank you very much and have a good day.

iPhone 15, iOS 26

Posted on Oct 1, 2025 8:07 AM

Top-ranking reply

Katana-San

Level 10

81,061 points

Posted on Nov 22, 2025 7:04 AM

Followyoheart wrote:

1. Following can be tried depending on your risk appetite. May not be advisable from safety point of view and depending on how essential are these features to you but could be done until the iPhone stabilises after updates:

Set all mail accounts to fetch manual. New mail only arrives when mail app is opened.

2. Turn off Siri learning for as many apps as possible that is not essential to you. You will have to go Siri settings. I have a feeling that the Apple Intelligence and Siri are using lot of phone resources to learn from your apps and phone usage behaviour.

3. Background activity still happens even if you set background refresh off. You can see that in battery % used for apps. It shows on screen % and background activity %. Close apps on your drawer once done.

4. Location services off for all non essential apps. It can be turned off completely as well until required during navigation but this is risky and not advised (I believe ‘find my phone’ will lose access unless lost mode is enabled from other associated devices) and definitely not for people who tend to misplace their phones. I’ve seen location services running every time I unlock my phone. This does drain battery.

5. Lastly 26.1 seems to have improved the battery management. Not sure though. Do not forget to update all apps and do a force restart before these measures.