User level: Level 1 (4 points)I upgraded to the latest iOS 27 on my iPhone 14 and my battery is gone down by triple the amount
Posted on Oct 4, 2026 3:22 AM
User level: Level 10 (97,882 points)Oct 4, 2026 4:29 AM in response to AlexanderK2O13
Welcome and thank you for reaching out. 🤗
A rapid battery drain after updating to iOS 27 can happen while the system reindexes and optimizes in the background, usually taking a day or two.
According to Apple: If you notice that your battery life has decreased after updating your device, wait a few days and then check again. Even though you can use your device immediately after an update, certain tasks related to the update continue in the background and might affect battery life and thermal performance. While they're ongoing, you might see the Insight Ongoing iOS Update in Settings ➢ Battery.
If you need more help, contact Apple Support directly.
Take care!
Smiliñ 😎 Brian | Community Volunteer
User level: Level 7 (20,243 points)Oct 15, 2026 8:51 AM in response to AlexanderK2O13
Your battery health and capacity has nothing to do with iOS 27. You just happened to upgrade to iOS 27 around the same time your battery was wearing out (close to 80%). That does not mean that iOS 27 caused the battery to wear out. It is close to worn out because it has been used a lot.
User level: Level 10 (105,996 points)Oct 15, 2026 8:35 AM in response to AlexanderK2O13
AlexanderK2O13 wrote:
Yeah, I’m 13 and in yr 9 but it didn’t say a battery warning before iOS 27 but now it does and my battery health is at 81% and it doesn’t do that on iOS 27 on my friends iPhone 17
Charge Cycles is the difference between your iPhone 14 and your friends iPhone 17. The iPhone 14 is only expected to last 500 charge cycles, while the iPhone 17 is expected to last 1000 charge cycles. After the update for about 4 days, there is always indexing being performed in the background, same is true for the previous iOS 26 and iOS 18 updates as well.
With your Battery Health at 81%, your phone is struggling to keep up. Typically replacement is done when it drops below 80%, but you are very close.
User level: Level 10 (107,674 points)Oct 4, 2026 5:47 AM in response to AlexanderK2O13
AlexanderK2O13 wrote:
... my battery is gone down by triple the amount
Meaningless. Did you mean...
Battery usage time from 100% to 20% in a day is one third of previously?
Or
Battery Health % is one third of what it was?
Or what?
How to write a good question for an iPhon… - Apple Community
User level: Level 1 (4 points)Oct 4, 2026 3:23 AM in response to AlexanderK2O13
I’m in the UK
User level: Level 1 (4 points)Oct 15, 2026 8:26 AM in response to LD150
Yeah, I’m 13 and in yr 9 but it didn’t say a battery warning before iOS 27 but now it does and my battery health is at 81% and it doesn’t do that on iOS 27 on my friends iPhone 17
Originally posted at discussions.apple.com/thread/256370146