iOS 27 battery life thread.

[goldmac2006]

Hey everyone, how’s WWDC 2026 treating you? We’ve heard a new iOS is coming out, and it’s time to dive into the iOS 27 battery life thread! It’s still surprising how many iPhone users are holding off on updating beyond iOS 18, especially since the Liquid Glass update drained battery health even with new features like Adaptive Power!

Want to see a quick rundown of iOS 26 battery life and health? Here are some highlights:

• Adaptive Power for Apple Intelligence enabled iPhones: users, no matter their iPhone model, said it wasn’t worth it. (This is enabled on default for iPhone 17 models) The dimming, reduced refresh rate, and any AI-supported changes to help battery life didn’t make a difference.
• Liquid Glass: a major reason for battery life issues because of increased graphics usage. You can find more details in this reel:
  in this new version, Liquid Glass will be more optimized.
• Less time and usage, plus a faster drain because of the same reason.

In my opinion, iOS 18 and 17 were a better story overall. Will iOS 27 be the end of the road?
There is also the new Apple Intelligence, powered by Siri AI, which might just help your device’s battery last longer with on-device improvements. If you’re interested, you can download beta 1 following the keynote!

(Moderators, could you please move this thread to the iOS 27 subform once it’s out? That way, we can keep things organized and avoid any duplicates.)

 

[goldmac2006]

Hey everyone, let me kick things off! 😊 Here’s how battery life looks 2–3 hours after updating to iOS 27 beta 1 on my iPhone 15 Pro.

I did notice a little warmth after leaving my iPhone on the charger a bit longer post-update, but it’s totally manageable vs last year when it felt like a hot flash .

Still feels like a bit of a drain though lol 😂 Dropped to 16% just 25 minutes after taking it off the MagSafe dock!

 

[krspkbl]

Too early to tell only been using it for a couple hours. First hour it dropped from 40-32%. I was just going through all my apps to check they were working and look to see what’s new. The phone is still indexing. Played a game for about 10-15 mins. Tried the extend/reframe feature in photos. Downloaded WatchOS to my series 11.

If there is any difference I can’t tell.

The phone got warm for a bit but now really cool. Will keep an eye on it.

 

[FeliApple]

• Adaptive Power for Apple Intelligence enabled iPhones: users, no matter their iPhone model, said it wasn’t worth it. (This is enabled on default for iPhone 17 models) The dimming, reduced refresh rate, and any AI-supported changes to help battery life didn’t make a difference.

I’m going to ignore the fact that this is AI nonsense for a second and address this:

It has always been impossible to optimise via settings the battery life loss caused by iOS updates. Adaptive power, disabling the usual settings, and any new settings that Apple may introduce with 27 for battery life will not be able to revert battery life to that of the previous version, if it is better.

It obviously may help relative to having that setting disabled on the updated version, but it doesn’t help vs older versions.

Now, previous performance-improving versions (like iOS 12), still came with a battery life impact. Let’s see if iOS 27 further worsens battery life or maintains it vs iOS 26.

I’m fairly confident in Apple’s ability to improve performance though, 26 was rather poor. But battery life will probably be worse.

 

[goldmac2006]

I’m going to ignore the fact that this is AI nonsense for a second and address this:

It has always been impossible to optimise via settings the battery life loss caused by iOS updates. Adaptive power, disabling the usual settings, and any new settings that Apple may introduce with 27 for battery life will not be able to revert battery life to that of the previous version, if it is better.

It obviously may help relative to having that setting disabled on the updated version, but it doesn’t help vs older versions.

Now, previous performance-improving versions (like iOS 12), still came with a battery life impact. Let’s see if iOS 27 further worsens battery life or maintains it vs iOS 26.

I’m fairly confident in Apple’s ability to improve performance though, 26 was rather poor. But battery life will probably be worse.

Not a one size fits all thing too; imo I’ll have to see bout it after a day passes. Right now keeping off adaptive power nor any low power mode on. The beta has been barely out for a few hours

 

[FeliApple]

Not a one size fits all thing too; imo I’ll have to see bout it after a day passes. Right now keeping off adaptive power nor any low power mode on. The beta has been barely out for a few hours

It can match (key emphasis on both words, can, and match) iOS 26, but it won’t be better. Hopefully it does match it, for the sake of all adopters.

Forget about the beta though, if you install the beta you know it can be awful.

 

[eoblaed]

It will be days before any battery life assessment will have any relation to reality.

I just upgraded 30 mins ago. My phone is quite warm, and likely will be for many hours, if not days, while it reindexes everything. This period of time will have a negative effect on battery life and performance while it’s don’t so.

There is no value in measuring battery life until that phase has concluded.

 

[SoYoung]

After updating my M1 iPad Pro it is extremely warm for hours now and lose 1% battery every 30 seconds to a minute. Anyone else? Even after a reboot the iPad is a normally hot.

 

[goldmac2006]

It can match (key emphasis on both words, can, and match) iOS 26, but it won’t be better. Hopefully it does match it, for the sake of all adopters.

Forget about the beta though, if you install the beta you know it can be awful.

Betas are always unstable in general , and it’s still quite early to say as much about it. We still have to wait at least 24-48 hours for it to settle in and stabilise like any other update and then do an actual test on it.

It will be days before any battery life assessment will have any relation to reality.

I just upgraded 30 mins ago. My phone is quite warm, and likely will be for many hours, if not days, while it reindexes everything. This period of time will have a negative effect on battery life and performance while it’s don’t so.

There is no value in measuring battery life until that phase has concluded.

After updating my M1 iPad Pro it is extremely warm for hours now and lose 1% battery every 30 seconds to a minute. Anyone else? Even after a reboot the iPad is a normally hot.

The heat issue imo was temporary, unlike in iOS 26 beta 1 it was really persistent. My iPhone did feel really hot at the start when the update just barely finished for the first hour then it settled down.

 

[SoYoung]

12 hours later my m1 iPad Pro is still extremely hot at a point it barely charge when plugged. First time I have this kind of issue ever and I install the first beta of major iPadOS version since a good 10 years. I think I'll have no choice to revert back to iPadOS 26 at this point. I don't want to hurt the iPad itself.

 

[xxFoxtail]

So far, battery life is a lot worse for my iPhone Air. Warms up a lot more than it did on iOS 26 too.

 

[lemonviking]

12 hours later my m1 iPad Pro is still extremely hot at a point it barely charge when plugged. First time I have this kind of issue ever and I install the first beta of major iPadOS version since a good 10 years. I think I'll have no choice to revert back to iPadOS 26 at this point. I don't want to hurt the iPad itself.

Weird. I have a m1 ipad pro too and it barely heats up.

 

[vbctv]

So far, battery life is a lot worse for my iPhone Air. Warms up a lot more than it did on iOS 26 too.

That's why I haven't installed yet, I had a bad feeling. Because I have noticed each 26.x update has caused the battery to get worse. On latest 26.5.1 I start at 6am at 100% and I'm down to 75% within 2 hours just from listening to Apple Music and using my bus pass. And it's still 100% battery health after just 219 cycles. I felt the best battery life on the iPhone Air was 26 & 26.1, after that it all went downhill...

 

[DblHelix]

In still waiting for indexing to finish nearly 24 hours after install.

 

[theappleloverguy]

That's why I haven't installed yet, I had a bad feeling. Because I have noticed each 26.x update has caused the battery to get worse. On latest 26.5.1 I start at 6am at 100% and I'm down to 75% within 2 hours just from listening to Apple Music and using my bus pass. And it's still 100% battery health after just 219 cycles. I felt the best battery life on the iPhone Air was 26 & 26.1, after that it all went downhill...

Are you planning to keep your iPhone Air or upgrade it this year, since the battery is taking a hit?

 

[goldmac2006]

In still waiting for indexing to finish nearly 24 hours after install.

Y’all this is the first time I saw this

Now it lets you know that your iPhone is indexing. In addition to setup or update in progress.

12 hours later my m1 iPad Pro is still extremely hot at a point it barely charge when plugged. First time I have this kind of issue ever and I install the first beta of major iPadOS version since a good 10 years. I think I'll have no choice to revert back to iPadOS 26 at this point. I don't want to hurt the iPad itself.

So far, battery life is a lot worse for my iPhone Air. Warms up a lot more than it did on iOS 26 too.

Weird. I have a m1 ipad pro too and it barely heats up.

That's why I haven't installed yet, I had a bad feeling. Because I have noticed each 26.x update has caused the battery to get worse. On latest 26.5.1 I start at 6am at 100% and I'm down to 75% within 2 hours just from listening to Apple Music and using my bus pass. And it's still 100% battery health after just 219 cycles. I felt the best battery life on the iPhone Air was 26 & 26.1, after that it all went downhill...

Looks like a mixed bag of heat issues here. Is it isolated to these models? My 15 pro only heated up a little bit after the update and that’s it.

 

[DblHelix]

Y’all this is the first time I saw this
View attachment 2636678
Now it lets you know that your iPhone is indexing. In addition to setup or update in progress.









Looks like a mixed bag of heat issues here. Is it isolated to these models? My 15 pro only heated up a little bit after the update and that’s it.

So far one of the worst first betas I have used and I am often testing the new os to get new features early. This time indexing more than 24 hours after install, heat issues, messages is all kinds of borked one message that no matter what I do will not get marked as read, half the time I get a new one I tap into it and can't read it just blank text block. Siri AI is slow as mollasses.

 

[cashville2400]

I came here to read everyone's experiences, and I'm glad I did. Right now, it looks like I will wait for the Pubic Beta, but even then, I will proceed with caution.

Typically, I download the betas, but I think I will wait this one out.

 

[DblHelix]

I came here to read everyone's experiences, and I'm glad I did. Right now, it looks like I will wait for the Pubic Beta, but even then, I will proceed with caution.

Typically, I download the betas, but I think I will wait this one out.

Overall most things are stable I think the heat issues will resolve when indexing completes and since they never told us when phone was indexing before I don't think people realized how long it was taking.

The messages bug is annoying and I hope they fix it have submitted feedback on it

 

[Barbs]

working well for me. Don’t miss out on the fun!

 

[Grayburn]

No complaints here so far but I did only install about 7 hours ago.

 

[krspkbl]

Battery stats say i’m using more than usual.

Last charged to 80% at 09:23. Currently at 45% and it’s 01:48 the next day. So lost 35% over 16.5 hours.

 

[goldmac2006]

Battery stats say i’m using more than usual.

Last charged to 80% at 09:23. Currently at 45% and it’s 01:48 the next day. So lost 35% over 16.5 hours.

was your iPhone heating up when it did that ? my iPhone 15 pro was of the same thing when it was fresh off the update, but stable thereafter. still accelerating on battery drain due to indexing.

So far one of the worst first betas I have used and I am often testing the new os to get new features early. This time indexing more than 24 hours after install, heat issues, messages is all kinds of borked one message that no matter what I do will not get marked as read, half the time I get a new one I tap into it and can't read it just blank text block. Siri AI is slow as mollasses.

Overall most things are stable I think the heat issues will resolve when indexing completes and since they never told us when phone was indexing before I don't think people realized how long it was taking.

The messages bug is annoying and I hope they fix it have submitted feedback on it

ngl my setup/updates usage was higher as my iPhone was downloading data for the Siri AI and apple intelligence files , for today. but my battery usage on my iPhone ain't hitting the orange marks yet.

unrelated thing here, but anyone who got new Siri AI and got off the waitlist, y'all saw your writing tools disappear? On my Mac it can't come back after a restart, but on my iPhone it did.

 

[Martincool22]

So about a day later I have seen a few small bugs and my iPhone 17 keeps getting hot/warm. But other than that performance seems faster than iOS 26 especially opening up apps. But it’s still processing/indexing in the background I will give it a few more days. Btw I got the new Siri AI I was off the waitlist after 22 hours.

 

[krspkbl]

was your iPhone heating up when it did that ? my iPhone 15 pro was of the same thing when it was fresh off the update, but stable thereafter. still accelerating on battery drain due to indexing.




ngl my setup/updates usage was higher as my iPhone was downloading data for the Siri AI and apple intelligence files , for today. but my battery usage on my iPhone ain't hitting the orange marks yet.

unrelated thing here, but anyone who got new Siri AI and got off the waitlist, y'all saw your writing tools disappear? On my Mac it can't come back after a restart, but on my iPhone it did.

My phone only got warm after updating to 27. Has been cool since never felt it get warm again.