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.