As another data point, I just had optimized charging turned on for my 1-year-old 15 Pro Max and it shows 183 cycles and 96% capacity. That seems right to me as I rarely go below 50% a day.
I see no advantage to limiting charging to 80% and when I go on hikes I want to make sure it’s at 100% just for safety reasons (it usually is at 100% because I drive to the trailhead while my phone is plugged into wired CarPlay).
How do you get that Shortcut to run automatically? I experimented with one to alert me when my phone goes below 50%, but I can find no way to trigger it automatically. It seems I have to explicitly run the Shortcut in order for it to detect the current battery level. Ideally I’d want something running all the time and alerting me the moment the battery goes below the level I set.
I couldn’t find a trigger like that in the Shortcuts library, but maybe I wasn’t looking in the right place?
Shortcuts app. Tap “Automation” at the bottom. Tap “+” top-right and choose “Battery level” (or, if it’s on an older version of iOS, choose “Personal Automation” rather than “Home Automation” first.). Then follow the prompts that you want to create the conditions (e.g. “Falls below” and use the slider above to change the default 50% to something higher or lower.) Also make sure that you choose “Run immediately” from this screen or it will prompt you rather than run automatically.
And then add the action “set low power mode”.
I also suggest creating another personal automation that turns off low power mode when battery level rises at least about 5% above where you set the threshold for low power mode, so you don’t have to think about it.
(My two thresholds are 25% for low power mode and 80% to turn low power mode off.)
Doh! That’s the step I was missing. I created a shortcut first and then was scouring the library for a way to trigger it. Never even noticed that “Automations” tab. Lots of cool stuff there. Thanks a million!
It was more common back in the days of PDAs, when batteries didn’t last as long.
I worked that way with my old Palm m515. I had three charging cradles - one on my nightstand, one on my desk at home, and one on my desk at work. The device was always sitting on one of them, except when I was actually traveling. So the battery rarely drained much.
I suppose I could go back to that model, but if I don’t spend a lot of time gaming on battery (I try to remember to be connected to USB power during long gaming sessions), a single overnight charge is good enough to get me through the day, so there hasn’t been much of a need to do so.
This reminds me of some of the “battery health” optimization suggestions for Tesla owners very much along the same lines. Both are lithium based and I’m uncertain other differences between Tesla and iPhone batteries otherwise. The exception is Teslas with LFP batteries (not lithium) that you can charge to 100% and not have the same concerns. They also recommend keeping Tesla plugged in and capped at 80% charge most of the time but ok to go 100% if needed (road trip coming up) on occasion.
Unusual!? We’re out there, buddy! 
Since 2007 I have always connected my iPhone to power before I go to bed and then shut it off (because if you shut it off and then connect it to the charger it will restart). Yes, I have an actual, like, alarm clock (not much used these days) and, yes, I still have a landline which I am now regretfully retiring because the cost has now flown well above the aggravation of changing innumerable accounts I haven’t looked at in years.
I don’t obsessively check such things but I’m pretty sure my iPhone 11 was still showing 80% when I traded it in this year. Not only do I start the day off fresh and cheery with 100% but I usually finish the day with a big margin. I don’t listen to music much on the phone, that’s what a fine stereo is for; nor do I watch movies or videos on it, that’s what that big screen in the living room is for. The only time iPhone use really goes up is when I’m traveling and making much more extensive use of the phone and it is awesome for that.
Dave
Hi Ace,
I’m a poor British pensioner with three iPhone 6s and an iPhone 12 Pro and ALL of their operating systems mess about with charging DELIBERATELY! Apple are NOT customer sensitive and I’ve given up talking to a “Genius” only to be told to “Update the iOS & re-start the unit”!!
ATB
Joe
Thank you very much, that was very helpful to me. Managed to set up 2 automations for my iPhone. 
Do you by any chance know how to set up something similar for turning on low power mode when an Apple Watch battery level falls below a certain level? I have tried to set that up but get stuck after selecting Apple Watch → + (New Shortcut) → Add Action → Set Low Power Mode and then If (Input) (Condition).
I am not at all enamored of this limited charging procedure for iPhone. I have turned it all off, Optimization and everything else. I was tired of it maxing out the charge at 97%. When I charge anything, including the iPhone, I want it to charge to 100%, period. I have an iPhone 11 Pro Max, which is 6 years old, and my battery capacity according to Settings is 84%. That percentage has not moved at all since early last year, and I am totally satisfied with that percentage, considering the age of this phone.
You have a group, don’t you?
As I recall, limiting the amount of charging (to 80%, for example) is available for only (certain?) iPhones 15 and 16.
The maximum can be limited to less than 100% on iPhones 15 and 16.
With iPhone 15 models, you can choose between Optimized Battery Charging, 80% Limit, and None.
When you choose 80% Limit, your iPhone will charge up to about 80 percent and then stop charging. If the battery charge level gets down to 75 percent, charging will resume until your battery charge level reaches about 80 percent again.
With 80% Limit enabled, your iPhone will occasionally charge to 100 percent to maintain accurate battery state-of-charge estimates.
Source
Yes, but you’re describing a different feature. The 80% limit (only available on iPhone 15 and later models) and optimized charging are different mutually-exclusive options.
I was responding to one person who wrote that “Optimized also limits the maximum charge”, which I don’t believe to be the case (at least on iPhones - one person wrote here that it does limit charging on Macs).
As far as I know there are no similar personal automation triggers for the Apple Watch, and no actions to turn on low power mode for the watch from a shortcut (though you can turn off always on mode and turn on theater mode, both of which could save power.) One way to trigger using an automation is to create a benign focus mode, because a change in focus is one way to trigger an automation.
I just checked my settings and I DO have “Optimized Battery Charging” available and it says it will limit charging to 80% “until you need to use it”. I have turned this OFF and will NOT use it for the reason I already stated.
As I understand, iOS monitors charging habits and with this setting turned on it will delay charging from 80% of capacity to 100% until close to the time that you normally disconnect from the charger. Again, as I understand, this delayed (80→100%) charging occurs at a lower wattage (and, consequently, slower rate) to prevent overheating. Thus this setting does NOT stop charging at 80% nor does it interfere with charging all the way to 100% of capacity; it simply simply slows down the 80→100% top-off.
“Optimized Battery Charging is available on all platforms as of iOS 13, watchOS 7, and macOS Big Sur. Based on your daily charging routine, it may automatically defer charging to 100% until shortly before you need to use the battery.”
Source
(See also @Shamino’s more detailed explanation.)
This Optimization is different from the option available for iPhones 15 and 16, which prevents charging beyond the specified level, e.g., 80%.
All I can tell you is that with that setting turned on, my iPhone would not charge past 97%.
Using the Battery setting, you can graph the battery’s charge for the last 24 hours. I’ve attached the graph for my iPhone 16. I placed the phone on a MagSafe charger when I went to sleep. It took about 1 hour for the charge to reach 80%, and charging ceased for about 2 hours. It took another hour for the charge to reach 100%, but trickle charging continued until I removed the phone from the charger when I awoke.
This is the biggest study that I’ve seen:
