I have been using my iPhone 16 Pro Max for a year. I enabled the 80% limit a few weeks after I bought the phone.
About two weeks ago, my battery health showed 100%. It has dropped to 98% now with 216 charge cycles.
Was it worth it for me to use the 80% option? It is complicated. This is the first time I have bothered about this setting. I did not care about that with my last iPhone (one year ago):
So, the iPhone 15 Pro Max battery was able to achieve 100% max capacity after one year because of my charging habits described in the quoted topic above without having the 80% setting enabled:
The iPhone gets its charge daily during the night between 3:30 and 6:30 a.m. via the Belkin Boost Charge Pro 3-in-1 Wireless Charger (the charger is sitting behind a smart plug that turns the power on and off at the times mentioned above).
With just the normal settings (optimized charging, no fixed level of 80%, daily charging for three hours, at always the exact same times - Apple is able to do its job preserving my battery’s health under those circumstances, without the 80% limit). And I get to use the full battery’s capacity if needed.
My iPhone 16 Pro Max battery still is in good shape after one year, but it is not at 100%, even with the 80% limit activated.
So, how did I get through my days with 80% enabled throughout the year? Well, mostly everything was just fine. But there have been days where I needed to look for an opportunity to charge my iPhone some days. And there have been days (probably a few dozen days over the year) when I ended up with 20% or a little less in the evening, which is not good for the battery either.
So, was it worth the hassle to limit myself to 80% battery given my personal experience? I think probably not in my case.
I am considering going back to optimized charging without caring about anything else.
Given my daily charging pattern of three hours from 3:30 a.m. to 6:30 a.m., the OS is able to charge to 80% and to only push the battery to 100% at about 6:30 a.m. Then the iPhone is being disconnected from the charger, and I am using it so that the battery level is going down under normal use, so that the battery will not stay at 100% for a long time.
The 80% limit is just great if you are reliably able to get through the day using less than 60% of the battery’s capacity. I am not able to do that, at least not every day.
EDIT:
I just switched to 100% and only then did I receive the prompt that a limit of 100% could degrade my battery health sooner and that - given my usage patterns - I should set the charge limit to 85%. Well, 85% it is then. Let’s see how this will play out. 