What would happen if the iPhone has learned my charging routines and all that, but for some reason there was one day in which I put it charging at 90%, with optimized battery charging on would it just keep going till 100 or go down to 80?
[Re-Titled by Moderator]
iPhone 13 Pro, iOS 18
See what you can glean from: About Charge Limit and Optimized Battery Charging on iPhone - Apple Support
No matter where you might have the Charge Limit set, the battery will still charge to 100% "occasionally" to allow for accurate battery calibration.
There are different opinions on how often "occasionally" might be with some users reporting that this occurs about once a month, some reporting less often and some reporting more often.
I don't understand the "go down to 80" part of your question, but if you set the Charge Limit to 80%, the battery will charge to 80% unless it goes to 100% "occasionally".
Personally, I think Charge Limits of 80, 85%, 90% etc. are more a gimmick than anything else, but that might be another discussion.
How does Optimized Battery Charging work on iPhone?
