iOS 11.3 Battery Health and Performance Throttling: what is it exactly?

iOS 11.3 Battery Health and Performance Throttling: what is it exactly?
One of the biggest new features in iOS 11.3 is a more advanced long-term battery health monitoring and the option to disable performance throttling, but how do you use these features and what do the numbers there mean?

It all started with an issue that affected iPhone SE, 6, 6s and 7 series of devices with older batteries. Those devices would unexpectedly start shutting down when an intensive app runs and to fix that issue Apple decided to quietly slow down the performance of these phones to avoid those peaks in power usage. This, however, resulted in phones running much slower than usual and a lot of perplexed users as to why this was happening. At the end of 2017, a user investigation found the link between degraded battery health and slower-performing iPhones, and multiple class-action lawsuits were filed against Apple for the company failing to disclose these tactics. Apple apologized and promised to give users more clarity about when their battery has actually aged to the point that it needs to be replaced and also allow users to disable the throttling that Apple applies (this way iPhones with older batteries would run faster, but still risk experiencing an unexpected shutdown).

This brings us to iOS 11.3 that finally introduces Battery Health Tools. The feature is in beta as Apple is still putting the finishing touches, but you can already get important information about your battery.

How do you use Battery Health?

If you have updated to iOS 11.3 (here is how to update), you can find the new stats under Settings > Battery.

Performance Management: here is what it is

Apple took some draconian steps to avoid unexpected shutdowns on iPhones with older batteries, which resulted in some phones running very slow. With iOS 11.3, the company introduces new measures and the update will actually bring your phone's performance to its peak state. Only then, if you experience an unexpected shutdown, the platform will use performance management to slow down your device, but in a much more subtle way.

For peak performance, you need good battery, but what does this mean?

In order to have your phone running at its optimal performance, you need your battery to be in a good condition. If your battery is too old, you will need to replace it with a new one. But how can you tell?

Here are the different messages that Apple displays depending on your battery state in long-term Battery Health menu:

  • 100%: Your battery is currently supporting normal peak performance.
  • XX%: This iPhone has experienced an unexpected shutdown because the battery was unable to deliver the necessary peak power. Performance management has been applied to help prevent this from happening again.
  • 79% or less: Your battery's health is significantly degraded. An Apple Authorized Service Provider can replace the battery to restore full performance and capacity.
  • Unknown: This iPhone is unable to determine battery health. An Apple Authorized Service Provider can service the battery.

What happens when I disable power management? Is that even safe?

With iOS 11.3, you also get the option to disable power management. When you do this, your phone processor will run at its typical speed, but when there is a power surge, you risk your phone unexpectedly shutting down. Here is an interesting detail: once that happens, your iPhone will restart and when it boots up, power management will be automatically enabled. So if you insist on using your phone with power management turned off and risk having unexpected shutdowns, you will need to re-enable this option every time your phone reboots from such a shutdown.

But in this case, is it even safe running your iPhone with power management disabled. Well... yes. You only risk your phone shutting down on you. Disabling power management only means that your phone will run at the same speed it ran when its battery was new. Apple will still do traditional power management, so you don't need to worry that your phone might explode or overheat.

Do unexpected shutdowns affect my iPhone 8/8 Plus/X?

While Apple has warned that all batteries degrade with time and its 2017 iPhone 8 and X series are not immune to that, the company also says that it has implemented a new and more advanced power management that should decrease the chance of an unexpected shutdown on these newer devices. So it seems that currently you do not need to worry about messing with the power management on Apple's latest phones.

Here is the company's explanation:

What about iOS 11.3 battery health for iPad?

The iPad has a much larger battery cell than iPhones, so it apparently has enough power to handle power surges even when its battery is older, so so far there have been no reports of throttled performance of an iPad.



1. rouyal

Posts: 1582; Member since: Jan 05, 2018

Downloading now on my iPhone 8 and iPad. Nice to have updates when they are released.

2. japkoslav

Posts: 1507; Member since: Feb 19, 2017

It's nice to have fixes, there I fixed that for you.

4. kiko007

Posts: 7493; Member since: Feb 17, 2016

Literally all software has bugs that need fixing... what's your point? Don't tell me you're one of the delusional nimrods who believe Android is faultless. If so, you're lying to yourself.

5. sissy246

Posts: 7111; Member since: Mar 04, 2015

Have to agree on the all software has bugs but, this bug was done deliberately with the throttling and not telling the truth. Also, there are just as many delusional apple ifanboys that thinks apple never has faults.

15. BuffaloSouce unregistered

Look at you trying to turn this into another squabble...notice how he said ALL software has bugs and didn’t say one OS has less bug than the other. You could be considered a fandroid by how many times you make things into android is better than Apple instead having a normal discussion

18. sissy246

Posts: 7111; Member since: Mar 04, 2015

Where did I say Android was better in what I wrote. I agreed with the ALL have bugs and ALL DO, But the fix for the battery was NOT a bug.

21. BuffaloSouce unregistered

Where did I say that you said android was better? I didn’t...I was stating how quick you are to always attack Apple and act like android is better when it actually comes down to personal preference

26. sissy246

Posts: 7111; Member since: Mar 04, 2015

"You could be considered a fandroid by how many times you make things into android is better than Apple" Exactly what you are saying right here.

32. T12RYK

Posts: 849; Member since: Jun 10, 2011

Its not a bug. Its a FEATURE! #AppleLogic

8. maherk

Posts: 6877; Member since: Feb 10, 2012

The difference with iOS, that with each update that promises to fix an old problem, it brings a new problem for the next update to fix, and so on and on.

10. AVVA1

Posts: 228; Member since: Aug 01, 2017

Hopefully this would get fixed on iOS 12

13. japkoslav

Posts: 1507; Member since: Feb 19, 2017

No, I use both platforms. Android certainly have its issues, but it was never as bad as iOS 11. When the new Android is released it works, when new iOS is released there are ton of bug and issues. I hate "we can't fix it later with dlc" attitude. Android is like Nintendo and Apple really close to EA quality.

14. rouyal

Posts: 1582; Member since: Jan 05, 2018

“When the new Android is released it works” “Android is like Nintendo” I think kiko got it right - “delusional”. You can call android a lot of things, but polished is not one.

17. japkoslav

Posts: 1507; Member since: Feb 19, 2017

On Android my battery was never cut in half, speakers did not start to bark for two weeks before they patched it, I haver never experienced issues with headphone amplifier, massive animation stuttering, if I chose to backup a folder it never backed up the WHOLE device with every folder and then started to whine "buy a bigger iCloud" and of course random stylus disconnects.

22. rouyal

Posts: 1582; Member since: Jan 05, 2018

I could name off a list just as long or longer for Android issues I’ve encountered, all the while I never experienced anything you listed on iOS. It’s amazing how different peoples experiences are. I use Googles apps and Drive on iPhone, not iCloud, so I’ll have to take your word for it. But, how and why, do you back up a “folder” on an iOS device? How do you even create a folder? You lost me there.

25. japkoslav

Posts: 1507; Member since: Feb 19, 2017

I wrote that backup thingy wrong I didn't want to backup one "folder", but backup everything BUT one folder that is huge and I don't care if it dies with some messed up update. In backup options I always checked not to backup that data, but everytime it was backed up anyway .... well it wasn't because it did backup something and than reached massive folder that was bigger than my iCloud ... so it failed and "five me money" message was displayed. Many many updates later, it was fixed. Plus I forgot chinesse and russian spam in my iCloud calendar! That was like an year of constant spamming.

12. rouyal

Posts: 1582; Member since: Jan 05, 2018

I meant what I typed. No fixing needed. Didn’t experience any issues or bugs prior to the update. I can’t say the same for my android phone on 8.0

19. Back_from_beyond

Posts: 1420; Member since: Sep 04, 2015

You wouldn't tell anyone here even if you did experience any issues or bugs.

23. rouyal

Posts: 1582; Member since: Jan 05, 2018

Well that sounds like your problem choosing not to believe me, not mine.

27. sissy246

Posts: 7111; Member since: Mar 04, 2015

No problems here with 8.0 on my note 8. That sucks if you are have bugs.

7. NateDiaz

Posts: 1088; Member since: Mar 03, 2018

Man, its 2.18GB here

3. Jrod99

Posts: 729; Member since: Jan 15, 2016

Installed last night and says I’m 83 percent on my 6s plus. About 2 1/2 years now. I thought I stay on phone too much but still performing great. Thinking this whole thing probably got blown out of proportion like most things do regarding this tech.

6. sissy246

Posts: 7111; Member since: Mar 04, 2015

All batteries degrade, it was the lying about it. If Timmy boy would have been honest from the get go it never would have been a big deal.

9. maherk

Posts: 6877; Member since: Feb 10, 2012

The 6s battery life was and still one of the best in the market, it never needed to be put on the charger at least twice a day. I would like to see the battery health of the regular iPhone 6 or 7, that would definitely be a different story.

11. rouyal

Posts: 1582; Member since: Jan 05, 2018

Got my 8 on Jan 29. Showing 100%

20. Back_from_beyond

Posts: 1420; Member since: Sep 04, 2015

If it showed anything else, you should be worried.

16. BuffaloSouce unregistered

Downloaded it yesterday and it seem to have helped my battery. Before I would change my phone before I go to bed and overnight it would drop a noticeable amount but didn’t happen this morning. We’ll see how it holds up throughout a full day

28. BuffaloSouce unregistered

*update* it been 6.5 hours and my I8 is only on 70 percent. My job requires me be be on my phone a lot so this includes on screen time

24. gamehead unregistered

I dont have the feature

29. RossoRider

Posts: 5; Member since: Dec 19, 2017

The fundamental error is not yet resolved ... the operating system is poorly designed as it does not work properly on all Apple mobiles. The so called battery health check does not solve the actual root cause of the badly developed operation software.

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