I really think it all depends on how you use your phone, or rather how much you use it! My phone doesn’t get too much use and I’m quite happy with 80% charging.
As I see it, the aim of optimized charging is to predict how you charge your phone, and in theory should only operate if it thinks it will be charging for an extended period. They say it’s clever enough to predict that it should be fully charged when it’s unplugged, whether that’s what happens in real life is anyone’s guess.
Apparently with 80% charging it will charge to 80%, and then monitor the charge down to 75%, and then charge back up to 80%. One thing it will do is occasionally charge to 100% in order to maintain the ‘state of charge’ accuracy.
For the meantime I’ll leave it at 80%, unless it starts getting more use, and I’ll then have to rethink it !
If you have a regular sleeping pattern, Optimized Battery Charging is better for your battery‘s health. The iPhone stops charging at 80 %, and start charging to 100 % in time, before you need it.
80 % means it stops charging at 80%, and will charge again when it‘s at 75%.
Thank you, Aerofly and J.A. Great information from you both. I use my phone a lot and rarely let it charge overnight. I use a USB-c cord in the car for Apple Car Play which trickle charges the phone. Otherwise, I charge as needed. I’ll leave it set to Optimized and see how it goes.