Battery Drain on iOS 26 and iOS 26.0.1.

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

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-.

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.

I am having the same problem and this ticks me off! My battery was fine until I downloaded the update several weeks ago. My battery has progressively gotten worse ever since. Apple needs to give us all new batteries!

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.

sk8gal wrote:

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.

Under the post you replied to it shows where that person directed their post. For example, you responded to Jeff Donald who was asking the question to muzckl1 and pertains to a completely different issue and that person is not experiencing the same Charge Limit issue you are having.

Dec 23, 2025 6:43 AM in response to muzckl1

As suggested previously, you should try charging your devices all night to see if the behavior changes. No one else on this megathread is experiencing the problem with the Charge Limit. As stated already, it is supposed to charge to 100% on occasion to maintain accurate reporting, so do not manually remove it from the charger before that time and give it the necessary time to update the battery settings while it is at 100%.

If not resolved that way, then schedule a service appointment at Apple. If it was a problem with iOS 26, then we would all be seeing it and also there were be tons of posts about it on this support site. The only posts found are those that did not realize it still needed charging to 100% at times and once they realized that and left their device alone it returns to the normal Charge Limit.

You also have the option to make a new post since your issue is not related to the battery drain issue reported here and this thread pertains to iOS 26.0.1 which is now outdated and not even signed by Apple to be used for an update.

Jim, I'm sure you mean to be helpful. Your responses are not helpful. I've worked with Apple products since the 1980s. I know when to make a service appointment. I've been observing the battery issues for a while now. No one at the Apple Store has a sufficient response. There are tons of posts about the battery issue. I have had Apple devices for so long now - I understand the charging behavior. THINGS ON APPLE'S SIDE OF THE EQUATION HAVE CHANGED.