After iOS 18.5 update my iPhone will not charge more than 80%

Post a screenshot of your Settings. Optimized charging is designed to charge to 80% when used on a regular schedule and will charge to 100% shortly before you normally take it off the charger. It takes a couple of weeks to establish that schedule and when taken off the charger too soon, you will only see the 80% charge. Turn off Optimized Charging if a schedule does not work for you.

It appears from the screenshot when you moved the slider to 100%, you did not choose the Set to 100% option. The other option is set until tomorrow, which is indicated by the message on the screen that it will return to your previous setting.

When you move the slider off 100% and back again, do you see those options?

Fuzzy2616 wrote:

I’m working in a war zone in Gaza , sometimes 24hr a day no 9-5 schedule , expecting me to now wait weeks for this newIOS AI to determine what’s best me me in charging levels is wrong , I need my phone to get 100% everytime

I'm not sure what you're expecting from us on this user to user only forum. We're telling you what will work under normal circumstances. The fact you're in in a war zone in Gaza is certainly stressful and dangerous and I'm sure the people you are helping are beyond grateful for your help. But there is nothing anyone here can do about your unusual circumstances as it relates to charging your phone.

It’s also possible that if you have set the limit to 100% indefinitely but your iPhone still stops at 80%, it could merely be pausing due to heat which definitely is generated when fast charging to 100%. When the iPhone does cool down, it would resume.

Hello!

How big in Watts is the adapter you use? Have you tried using different adapters, cables, etc.? Have you tried charging with Optimized Charging OFF in: Settings > Battery > Charging?

Thanks.

You aren't speaking with Apple, so no one can fix anything on this user to user only forum. You're the first person I've seen suggest your phone won't charge to 100%, so I'm not sure Apple has anything to fix to begin with. We have iPhone 16 Pro and 16 Pro Max. We charge our phones at night, every night, all night and we wake to phones charged to 100% every morning.

Did you set Optimized Charge Limit on your phone, which does stop the charge at 80% by design (with occasional charges to 100%)?

There are two options in Settings > Battery > Charging. You can set a charge limit from 80% to 100%. Or you can just turn on Optimized Battery Charging.

This is a user-to-user technical support forum. No one here did anything to your phone. Cursing at people here will probably only result in you getting less help.

Three people have asked you for more information. If you want help, answer the questions and provide that information.

It appears you have set a charge limit and NOT turned on Optimized Battery Charging. Turn on Optimized Battery Charging, then plug it in to charge when you go to bed at night and leave it plugged in to charge ALL night EVERY night.

Fuzzy2616 wrote:

No matter what I do with battery settings and optimized battery or off , 80% is highlighted in green and my phone will not charge past that !

You are confused. The 80% charging limit that is highlighted is a suggested Charge Limit, and from the subtitle it says you selected it to charge to 100% only once then for it to return to 80%. If you wanted it to always charge to 100%, you should’ve selected Every time. Drag the slider off 100%, then back on, it should ask you how often you want to use that, select always. Then turn on Optimized Battery Charging with it.

You may want to get a battery pack until this is resolved.