Translated by google:
>>iPhone 15 Pro, iOS 27
Hello! I need help figuring this out—the Optimized Battery Charging feature isn't working on my phone!
Here are the details:
The charge limit is set to 100%, and Optimized Battery Charging is enabled. I plug the phone in to charge overnight at home at roughly the same time every day, for a total duration of about 7 hours. I’ve been trying this since July, so the 14-day learning period should have been completed by now! I updated the phone to iOS 27 on September 14, and more than 14 days have passed since then as well.
In the Location Services settings, the following are enabled: Find My iPhone, System Customization, Emergency Calls, and Significant Locations & Routes. This section shows 117 Significant Location entries for the period between July 8 and September 29, 2026.<<
If you set the charging limit to 100%, the iPhone will only charge within a couple of percent, when having been charged to 100% before.
...
With iPhone 15 models and later, if the charge limit is 100 percent, you can also turn on Optimized Battery Charging. Your iPhone has these settings by default.
Your iPhone will charge to within a few percentage points of your chosen limit and then stop charging. If the battery charge level drops more than 5 percent while connected to power, charging will resume, again charging to within a few points of your chosen limit.
If iOS determines that a charge limit will help preserve your battery's lifespan, you'll see a recommendation. For example, you might see "Based on your iPhone habits, a charge limit of 95% is recommended to help preserve your battery."
If you have Charge Limit set to less than 100 percent, your iPhone will occasionally charge to 100 percent to maintain accurate battery state-of-charge estimates.
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copied from: About Charge Limit and Optimized Battery Charging on iPhone - Apple Support
