It doesn't charge the battery over 80% at all, unless it detects that you have a normal waking time, in which case it charges fully right before you normally wake up.
Unfortunately, other companies copied the 80% charge bit without copying the part about figuring out if you have a normal waking time and giving you a full charge right before that.
For instance, Samsung's S23:
>Once you turn off the battery protection function, you'll be able to charge your battery up to 100%
https://www.samsung.com/ae/support/mobile-devices/battery-pr...
My iPhone disagrees with you. I go to bed and wake up at just about the same time. If I somehow managed to drain the battery below 80%, when I plug it in, it'll charge to 80 and then tell me that by the time I wake up in the morning, it'll be fully charged. Which is the case.
But the most common use case, for me, is waking up, leaving the phone plugged in (WFH). Maybe go for a walk around noon, snap a picture or two. Forget to plug it back in and get back to work. Plug it in as I go to bed at 95%. It tops right up, doesn't wait until the morning.
> Unfortunately, other companies copied the 80% charge bit without copying the part about figuring out if you have a normal waking time and giving you a full charge right before that.
But that's actually what I want. With very, very rare exceptions, I never need a full charge on my phone. Hell, until a few weeks back, I was rocking an iphone 7 with a battery in a questionable state (started bulging). That thing never went below 60% with my use patterns. 60% meant night out, so a hefty dose of maps use. Normal days, it didn't go below 85-90%.
I think the issue is that Apple expects that when you wake up in the morning, you unplug your phone for the day and actually use it a significant amount. Which isn't my case at all. If I don't leave my house, it'll stay plugged in. I usually forget about my phone since everything I need to do, I do on my computer. For the occasional phone call, I can either keep it plugged in (the cord is long enough) or it's already connected to my headset, so don't even need to go fetch the phone. If I don't go to work, it can stay plugged in for days on end (I don't always grab it when I go out).
Why protect your battery's ability to hold a full charge over a longer lifespan if your battery is constantly throttled to a partial charge anyway?
I've used my old phone for a good six years. I've swapped its battery some three years ago, and it would've needed a new one now, had I continued using it.
If that phone is any indication, my current one should be in service for at least as long. If I can avoid having to swap its battery, it's a win in my book.
It can also sometimes happen that I foresee being away from an outlet or otherwise need as much charge as possible. In those situations, I'd just deactivate the battery saver feature and let it charge to 100%. So if the remaining capacity is closer to its original one, again, it's a win.
If you don't charge fully until just before the user's normal wakeup time you aren't keeping it all the way full all the time.
You protect the battery lifespan and get a full charge at the beginning of the day, instead of having a battery that constantly holds less charge.
You keep repeating this and seem to ignore my observation that if the battery isn't drained below 80% when I plug it in, it will recharge it fully immediately. It will not wait until the user's wake-up time.
And in my case, it's rare that the battery falls below 80%, so whenever I plug it in, it gets recharged fully right away.
So, in practice, it's all the way full all the time.
Yet year after year, surveys show that more battery life is the feature people want in a phone the most.
> 9 out of 10 phone users have low-battery anxiety
https://electrontogo.com/blog/9-out-of-10-phone-users-have-l...
Intentionally throttling the battery's ability to charge no matter what is going the wrong way.