iPhone 15 charging optimization limit exceeds 80%

From the Apple article:

About 80% Limit with iPhone 15 models

With iPhone 15 models, you can choose between Optimized Battery Charging, 80% Limit, and None.

When you choose 80% Limit, your iPhone will charge up to about 80 percent and then stop charging. If the battery charge level gets down to 75 percent, charging will resume until your battery charge level reaches about 80 percent again.

With 80% Limit enabled, your iPhone will occasionally charge to 100 percent to maintain accurate battery state-of-charge estimates.

This implies that it is around 80% not necessarily exactly 80% so it may still be working as intended. You could report it to Apple if you think it is a bug and not functioning correctly though

About Optimized Battery Charging on your iPhone - Apple Support

There was a know bug with this feature in earlier versions of iOS. Update your iPhone 15 to the latest version and the issue should be resolved.

Note, the iPhone may still charge to 100% sometimes to calibrate the battery.

Using iPhone 15 with latest OS updates.

With 80% Limit enabled, your iPhone will occasionally charge to 100 percent to maintain accurate battery state-of-charge estimates.

In case if it charges above 80% always, that’s a thing to worry..!

There are two possible causes

(a) (unlikely) The battery was fully charged when you started, and had only dropped to 86% by the time you looked.

(b) A software bug. Based on my observation of something similar with my iPhone 15 Pro Max, I think this is the likely cause. It should be fixed in a future software update, and speed of action will depend how many bug reports Apple gets for it.

Please post bug reports to the official Feedback pages for the device involved.

Feedback - iPhone - Apple

Apple states very clearly that the phone will charge above 80% up to 100% "occasionally".

The real question here is what exactly is meant by "occasionally". For some users, this might be every 7-10 days, others a few weeks and yet others every 4-6 weeks.

Having tried it both ways, I get better battery performance enabling Optimized Battery Charging and turning Off the 80% gimmick. Soon, there will be other new "gimmicks" in a new iOS version.

I connect the phone to the adapter at night and leave it connected all night.....every night.

This way, I start every day with the battery at 100%. If my battery dies a few months earlier than other users who are using 80% and charging more often, I could care less.

With 80% Limit enabled, your iPhone will occasionally charge to 100 percent to maintain accurate battery state-of-charge estimates-Apple

Try to turn off charging restriction, restart the phone, set the 80% option again and let it charge. In my case two times it charged the batt to 100 and now it always stops at 80. But I think that in some time it will charge to 100 again to just calibrate.

Update to iOS 17.2

first time to charge my 15 pro max. Went to get it off charger and noticed it was at 91%. Was supposed to stop at 80% according to settings. I created automated shortcut to notify me when charging rises above 80%. I wear an Apple Watch. It dinged my watch when I created a shortcut to notify me when it dropped below 90. So I can go in and unplug it when it gets to 80 until apple comes out with a fix

You may have missed the part in the documentation that says that the battery will still charge to 100% on occasion. "On occasion" for me is about once or twice a week.

Nothing really to be all that concerned about here in my opinion.

I realize that the battery is going to go for about 2 years and a replacement will be needed at that time. Day to day or even month to month, I just don't pay much attention to the battery.

I would recommend turning the feature off, powering off the iPhone, turn it back on after about an hour, then torn on the setting,

power off the phone again, then turn it on again after about 15 minutes. This should work as I have an iPhone 15 and used this myself.

I had similar issues when I first bought my iPhone 15. It turned out the problem was with the charger brick I was using. Once I changed the charger brick, the issue stopped, and I've had peace of mind since then

try to update your phone to 17.1. After update I did not see any “overcharge” on the phone. Or maybe the calibration thing worked for me - because it was charging for 100 two or three times ina row.

Harbeth wrote:

It did it again, unfortunately. It charged to 100%. Could the fact that I was using a cheap generic USB-C cable have anything to do with the problem?

Unlikely. I'm seeing similar behaviour using all-Apple cables and power adaptors.

I suggest changing to Optimized Battery if there is a setting for this in your charging options (it may vary a little depending exactly which model and software version). Settings > Battery > Battery Health & Charging

This is a relatively minor problem and will not harm your new iPhone if it charges to 100% a few times. It might make a very small difference in long term usage, but I expect this problem to be resolved sooner rather than later.

Update: after 10 to 15 fully charging to 100%, the phone now started to charge to the 80% limit. For a few weeks now, and it did not yet charge to 100% for calibration. So the functionality finally works for me.