Battery Drain on iOS 26 and iOS 26.0.1.

VictorSMiller wrote:

Why do you ask that we post screen shots, when you never respond to that posting?

In your specific case, you did see that my personal recommendation is for you to contact Apple directly for phone diagnostics. The same recommendation was followed up by lobsterghost1. It is through those screenshots where a problematic app can be identified. It is because of those screenshots that should also be useful for you so you can see no one else is experiencing the same FaceTime battery draining issue and a good reason why you need to contact Apple directly. You are also able to see by viewing my subscriptions and even in this thread in particular that I have been very active as far as following up on those posts.

When asking for help on a Support Site it is absolutely necessary to provide the relevant information for the problem you are investigating. Simply saying your battery is draining without providing this information is not useful to anyone. That information is not only valuable to me for a response, but also all the others who are looking to provide assistance. You will also be able to find that certain apps have been identified from a users post and when it was removed they were back to all day battery life. By providing those screenshots, you are able to compare the apps installed that are the same on other users devices experiencing the same thing. That is just a basic step for troubleshooting.

Right now is later in the 24 hour period. Watch the numbers change and the 24 hour period changes. My explanation also accounts for what happens when an app is deleted. Its prior usage doesn’t/can’t change. Just take a few moments and think about it.

VictorSMiller wrote:

The question is: why does the battery keep being used by FaceTime long after the call is over?

I think that has already been answered where the percentage does not immediately calculate when you quit using the app and the numbers you see are not in real time. That is why you see a different number than what you see immediately after closing the app. It works the exact same way in the example given about step count calculations in the Health app, where you can walk 500 steps and immediately look in the Health app and see they are not recoded, yet some time later you can look again and see the 500 steps number.

That is super easy for you to test where you will find your answer. Start your day with a 100% charge, then record a video for about 5 minutes. Check your battery percentage for the camera app you will likely see nothing or very little. Then check again later and you will see the percentage updated when those results were calculated showing they are not real time values.

It’s relative to the period of time. At what point in the day (number of hours) are you measuring the percentage of capacity used? I can’t give specifics without seeing screenshots of the actual graphs. The support articles are accurate.

Please point me to the exact article. Your explanation violates basic arithmetic. If the denominator (total usage) increases, the percentage used by an app that is no longer running should decrease, not increase. What you claim to be saying is that the percentages used by the apps are not the actual percentage used.

Please start with the article linked below and then read the articles linked to within the article. In all, about 8 to 10 articles need to be read to fully understand what’s being displayed, why it’s displayed and how to interpret the readings.

Check battery usage on your iPhone - Apple Support

VictorSMiller wrote:

That article tells me nothing concrete about the percentages corresponding to what you said. I tried clicking on the links, but none of them said more. BTW I used to be a Professor of Math and CS. I would give these articles a grade of C-.

Hello~ Let Apple know…

Product Feedback - Apple

Contact - How to Contact Us - Apple

Contact - Official Apple Support

Perhaps one of these links will make the grade?

~Katana-San~

You need to keep clicking the links within each article. The articles are intended for the average consumer. They are written in layman terms, but as you keep digging deeper you can put it all together.

The alternative is become an Apple developer and you’ll have access to Apple engineers. You can ask all the questions you want and they should be able to provide the technical explanations you may be looking for.

sk8gal wrote:

Several charges later, it appears that the setting is being ignored altogether for both the iPad and the iPhone. It charges to 100% every time (unless I remember to check it and remove it around 80%)

Schedule an appointment with Apple so they can perform diagnostics on your device. None of use are experiencing the same thing with a Charge Limit other than the occasional charging to 100% to maintain accurate estimates. If that action was due to the update, then we would all be experiencing it, so there is something specific with your device where it is not performing correctly.

Genius Bar Reservation and Apple Support Options - Apple

The first thing they will likely do is a Factory Reset, so if you have not done that already, then you may want to do that before scheduling an appointment to see if that resolves the problem.

What device and what iOS are you using? What is the battery health of your iPhone? Are you aware that batteries do not age in a linear fashion? It’s not unusual for battery health percentage to fix at one point for an extended period of time and accelerate at others. It can also be the result of changes (tweaks) in the algorithm used to determine battery health.

sk8gal wrote:

I did that two weeks ago. Everything is fine. This 80% battery charge limit is being ignored on both the phone and the iPad (the iPad is new). Something is amiss that is not specific to my devices.

The problem is that it is not being reported on anyone else's device. The only time that has been reported is when the user was unaware that it needed to charge to 100% on occasion to maintain accurate readings and once informed to not pull the plug early, the Charge Limit returned. If there was a bug in the update the ignored the Charge Limit, then this Support Site would be flooded with those posts, and that does not seem to be the case. It would also be easy for others to reproduce.

I haven't seen how long you have left it to charge while being on 100%, but would suggest leaving it plugged in all night to see what happens.

muzckl1 wrote:

I am having the same problem

And what is your Battery Health?

Your battery will only get worse until it needs replacing when the Battery Health drops below 80%, no matter what iOS version you are using. The effects are more noticeable the lower the battery health is.

muzckl1 wrote:

I updated well over a week ago and my battery is now at 79%. Before the update, my battery was at 90%. This is unreasonable.

What device are you using and do you know the Charge Cycles. An iPhone 15 and newer is expected to have 1000 charge cycles before the battery needs to be replaced when it falls below 80% and an iPhone 14 and older device is only expected to last 500 charge cycles. For an iPhone 15 a newer that translates to about 1% of Battery Health for every 50 charges cycles and earlier devices would be 1% for 25 Charge Cycles. The OS version makes no difference on the battery expectations of those devices.

Let us know the device and charge cycles if available and that will provide a better picture.

muzckl1 wrote:

I updated well over a week ago and my battery is now at 79%. Before the update, my battery was at 90%. This is unreasonable.

Has the battery ever been replaced? Third party batteries are well known for that type of behavior.

I have already put that information in other places in this mega thread. iPhone 13 mini, iPad A16. Both running iOS 26.2 I used to troubleshoot computers for a living. There is trouble somewhere in the iOS 26 upgrade.