Phone keeps shutting off and restarts on its own after the iOS 26 update

Abhish10 wrote: "...My battery health shows that it is at 73%..."

Abhish ~ That's well below Apple's suggested level of 80% for replacing the battery and explains the unexpected behaviour you're seeing. And it was probably at most 74 or 75% when you initiated the upgrade to iOS 26 just some days ago.

...So the upgrade didn't damage your iPhone — it just weakened further what was already a battery in need of teplacement. To avoid such situations as yours, I think Apple should advise users to check the Max Capacity before updating iOS.

iPhone Battery Service

About genuine iPhone batteries

Repair Provider Verification

(Articles found by searching Apple's Knowledge Base.)

õ¿õ¬

Abhish ~ Your iPhone 13 Pro could be 4 years old and the long process of applying an iOS update to an iPhone with a weak, aging battery can be the proverbial "straw that broke the camel's back." (And a degraded battery can cause shutoffs & overheating during charging.) So...

Does your iPhone 13 Pro still have its original battery?

And what's the Maximum Capacity % here?...

Settings > Battery > Battery Health & Charging

õ¿õ¬

Abhish10 wrote:

Also, while i agree with you, I feel it is wrong of Apple to provide me with an update that broke my phone. It was working completely fine until I updated to iOS 26. I think it would have been wiser for them to limit it to the phone that can actually handle the iOS. Now instead of buying a new phone , I will have to spend money to get a new battery?

Seems like a cost I could have easily avoided if Apple was transparent about the new iOS messing up older iphones. Just feel like an attempt to ensure they get a surge in support billings by enticing the users with new iOS and not telling them it has the ability to cause hardware damage.

I haven't done it yet, but definitely would feel cheated if I have to replace the battery tomorrow when I visit the service centre. Curious to know what the community feels about this.

The phone got here due to lack of servicing.

1. the battery should have been replaced at 79%
2. you MUST take an iCloud backup NOW while it is still working, or be fully sync’d with iCloud in every category, or you will lose your photos and data when it eventually fails

andydrummond wrote: "...my iPhone 13 mini restarts at night on charge since iOS 26 (only notice this because I’ve got a SIM PIN set). Battery health is about 83% so not that..."

andy ~ If your iPhone 13 mini is 3–4 years old, still has its original battery and is exhibiting other 'unexpected behaviours', the restarts could be battery-related. That 83% maximum capacity is only an algorithmic estimate of a dynamic, chemical process — so the battery's actual health could be worse than it appears.

õ¿õ¬

"Phone keeps shutting off and restarts on its own after the iOS 26 update: [...]After that, the phone just keeps on shutting down and restarting on its own. Now, I cannot use my phone because it gives up on me unannounced. Does anyone have any suggestions? P.S I do not have iCloud backup."

-------

Fixing a Boot Loop:

Your iPhone is stuck in a Boot Loop. This typically occurs when you go about installing an update, and it stalls during the process. So, Use my User Tip: How to Fix an iPhone in a Boot Loop - User Tip

Abhish10 wrote: "...after a two visits to the service centre..."

When you enter that service centre's address at the link below, does it get a green ✅ checkmark indicating that it's an 'Apple Authorized Service Provider'?...

Repair Provider Verification - Official Apple Support

...If not, that explains why they didn't simply replace the obviously depleted battery, but instead try to charge you for a new motherboard that's probably unnecessary.

õ¿õ¬

kiruthiga195 wrote:

Hi After iOS26 update my iPhone battery health is getting totally down and this kind of already I communicate with customer care in apple, once a time iOS 18 updating time my iPhone battery getting downed then after now I upgraded the iOS26 update, the battery totally fully downed

As you have been to Apple Support and they agree your battery health is below 80% then have them fit a new battery.

julinenenana wrote:

Same, I just set up a new bought refurbished iphone 13 mini with new battery (100%) and it reboots randomly both while in use and when left alone.

I also have the issue with loosing my bluetooth connection ~ every 10 Min 😒.

I tried to disable all fancy ios 26 settings and did a reset but the issue didn't disappear.

If Apple fitted the battery use your 90 day warranty

Hi After iOS26 update my iPhone battery health is getting totally down and this kind of already I communicate with customer care in apple, once a time iOS 18 updating time my iPhone battery getting downed then after now I upgraded the iOS26 update, the battery totally fully downed