How can I improve iPhone 15 Pro battery life after iOS 26 update?

What is your battery health? And a drop of 50% during the day is in the normal range. If you charge overnight every night, ideally with Optimized Battery Charging enabled (instead of 80%) and you reach the end of the day without have to recharge your phone is behaving as expected.

In the train, what is your cellular signal strength? A moving phone must “check in" with towers regularly, and, if the signal is weak that can consume a huge amount of energy. Likewise when you are in your office, what is the signal strength?

Also, from→About Apple software updates - Apple Support:

Immediately after completing an update, particularly a major release, you might notice a temporary impact on battery life and thermal performance. This is normal, as your device needs time to complete the setup process in the background, including indexing data and files for search, downloading new assets, and updating apps.

Massiefstaal wrote:

May I ask why that is? Everywhere you look/search they say charging til 80% will make your battery have a longer lifetime and makes the lithium battery health degrade slower. I’m curious why optimized charging is better.

No, “everywhere” does not say this. A few misguided individuals have extrapolated from the fact that EV manufacturers recommend not charging above 80% except for planning long trips. And it is simply that charging above 80% is less efficient. You should not leave any LiIon battery charged to 100% for long periods of time (weeks), and a car may be left idle for long periods of time. A smartphone will never be unless you turn it off and put it away in a drawer for weeks.

And it’s also based on the fact that you can’t drive an EV while plugged in, unless you have a very long extension cord. But you can use an iPhone while it is plugged in, and Optimized Charging gives you the best of both worlds, because it only charges to 80% until an hour before you are likely to use it, then boosts it to 100% at the last minute. And this means that the iPhone will use line power for most of the night instead of the battery, thus reducing the number of charge cycles over the life of the battery.

You can use 80% if you leave it plugged in overnight and get the same benefit but for less convenience.

Everywhere you look/search they say charging til 80% will make your battery.......

Well, I don't have the time to look everywhere, but the places that I have looked almost never tell you that charging the battery to 80% means that you will have to charge the battery more often. That's more wear and tear on the battery.

My phone would not make it all the way the through the day and into the evening when I tried the 80% setting, but it works great if I use Optimized Battery Charging and leave the phone connected to the charger at night....every night.

The phone stays charged at 80% most of the night and only moves up to 100% an hour or two before I unplug it to start the next day.

Yes, it is true that leaving the phone at 100% for long extended periods is not good for the battery, but that is not what Optimized Battery Charging is all about.

If "Charge Limits" were really important, don't you think that Apple would build this into all new versions of iOS? You only get Charge Limits if you have an iPhone 15 or higher.

Somehow, things worked just fine for 15+ years without Charge Limits.

My opinion.....Charge Limits are more of a gimmick than anything else.

80% will not give you a longer life span. Optimized charging will.

Learn why ⇢ the battery in your iPhone drains too quickly for details.

Good luck! 👋🏼😉

Excuse me @Lawrence Finch but how do u add your photo to your account avaatre thing???

According to Apple:

When you reach level 3 by earning 500 points, you will have the ability to upload a custom avatar image.

Good luck! 👋🏼😉