iOS 18 Battery Life Thread

[FeliApple]

Last time before I let the XR go it was on 18.2 developer beta 2. My 15 pro is on 18.3.1

After I upgraded to the 15 pro I reset the XR, and gave it away to my mother.

Yeah, it gave you 2-4 hours vs 10 for the 15 Pro because you updated it through 6 major versions. iOS updates destroy battery life when you push it far enough, that’s no secret.

I’ve been running iOS 12 since I got the iPhone Xʀ. I’ll be running iOS 18 on the iPhone 16 indefinitely if I hopefully get it.

Barring these specific iOS 18 issues for all iPhones, the #1 tip I can give you when it comes to battery life is to never update.

You’ll never get good battery life on an iPhone updated through six major versions.

 

[Artemiz]

Yeah, it gave you 2-4 hours vs 10 for the 15 Pro because you updated it through 6 major versions. iOS updates destroy battery life when you push it far enough, that’s no secret.

I’ve been running iOS 12 since I got the iPhone Xʀ. I’ll be running iOS 18 on the iPhone 16 indefinitely if I hopefully get it.

Barring these specific iOS 18 issues for all iPhones, the #1 tip I can give you when it comes to battery life is to never update.

You’ll never get good battery life on an iPhone updated through six major versions.

That’s cuz every iOS adds functionality while the processors stays the same on an aging battery. While technically true, you’re ignoring the biggest variables that’d account for the change. iOS optimizations would negate some of that but it’s still the same old processor and battery. There’s no hidden conspiracy there.

Would you expect to get the same things you did for $10 about 20 years ago as you do today?

 

[FeliApple]

That’s cuz every iOS adds functionality while the processors stays the same on an aging battery. While technically true, you’re ignoring the biggest variables that’d account for the change. iOS optimizations would negate some of that but it’s still the same old processor and battery. There’s no hidden conspiracy there.

Would you expect to get the same things you did for $10 about 20 years ago as you do today?

No, I’m not expecting anything, I’m just providing the cause.

Because I don’t expect battery life to be as good with many major iOS updates, I don’t update. That’s why I mentioned that comparing an iPhone Xʀ on iOS 18 to an iPhone 15 or 16 Pro on iOS 18 isn’t really fair.

And that’s why I’m running iOS 12 on my iPhone Xʀ and will run iOS 18 on the iPhone 16 indefinitely.

 

[Artemiz]

No, I’m not expecting anything, I’m just providing the cause.

Because I don’t expect battery life to be as good with many major iOS updates, I don’t update. That’s why I mentioned that comparing an iPhone Xʀ on iOS 18 to an iPhone 15 or 16 Pro on iOS 18 isn’t really fair.

And that’s why I’m running iOS 12 on my iPhone Xʀ and will run iOS 18 on the iPhone 16 indefinitely.

Your cause is flawed is what I’m saying since you’re ignoring everything else that could contribute to the battery drain.

Another flaw is that optimization’s been the #1 focus for iOS 12 instead of features. You’re running the most optimized iOS on its corresponding CPU iteration.

 

[FeliApple]

Your cause is flawed is what I’m saying since you’re ignoring everything else that could contribute to the battery drain.

Another flaw is that optimization’s been the #1 focus for iOS 12 instead of features. You’re running the most optimized iOS on its corresponding CPU iteration.

Agreed, but in my experience, there isn’t much you can do to optimise an inefficient and massively updated iOS version on an older device.

I’ve used both outdated iOS versions and obliterated, updated devices.

With an original iOS version I get a million hours. With an updated one battery life is garbage and no amount of usage patterns and settings optimization can fix it. It is what it is. I have accepted this.

So hopefully battery life on the 16 Pro models improves on iOS 18. For, say, the 13 and below there’s pretty much no solution.

 

[Artemiz]

Agreed, but in my experience, there isn’t much you can do to optimise an inefficient and massively updated iOS version on an older device.

That’s my point. You can’t defy physics. Apple could’ve done better if they put more resources into optimization but at some point it stops being economically feasible.
Everyone would like an iOS 12 style optimization cycle every 3 years. That’s something I believe everyone here would agree on.

So hopefully battery life on the 16 Pro models improves on iOS 18.

15 and 16 series do have some AI running constantly so the improvements might not be as dramatic.
iOS 18.6 or 18.7 is when it’d have been thoroughly optimized but with AI on iOS still being in infancy that’s not a given either.

 

[Populus]

Everyone would like an iOS 12 style optimization cycle every 3 years. That’s something I believe everyone here would agree on.

Definitely. I think iOS 19 or 20 is a good opportunity for that. On iOS 19 they are working (just my wild guess) on pushing even further the AI capabilities and Siri. I think there’s room to also focus on polishing long lasting bugs that maybe aren’t that common.

 

[goldmac2006]

Yeah, it gave you 2-4 hours vs 10 for the 15 Pro because you updated it through 6 major versions. iOS updates destroy battery life when you push it far enough, that’s no secret.

I’ve been running iOS 12 since I got the iPhone Xʀ. I’ll be running iOS 18 on the iPhone 16 indefinitely if I hopefully get it.

Barring these specific iOS 18 issues for all iPhones, the #1 tip I can give you when it comes to battery life is to never update.

You’ll never get good battery life on an iPhone updated through six major versions.

Agreed, but in my experience, there isn’t much you can do to optimise an inefficient and massively updated iOS version on an older device.

I’ve used both outdated iOS versions and obliterated, updated devices.

With an original iOS version I get a million hours. With an updated one battery life is garbage and no amount of usage patterns and settings optimization can fix it. It is what it is. I have accepted this.

So hopefully battery life on the 16 Pro models improves on iOS 18. For, say, the 13 and below there’s pretty much no solution.

Is this another reason why some users are still using iOS 17.7.4? I noticed a few iPhone users in the iOS beta threads mentioning battery life as a reason for their continued use.

 

[FeliApple]

15 and 16 series do have some AI running constantly so the improvements might not be as dramatic.
iOS 18.6 or 18.7 is when it’d have been thoroughly optimized but with AI on iOS still being in infancy that’s not a given either.

You know, I’ve always struggled with this. I know I’ll never update to any major version... but do I stay on, say, 18.4 on the iPhone 16 or do I update to iOS 18.7 or 18.8? Perhaps, for long-term use, those are better.

So far, I’ve never hit the update button, so my 6s remains on iOS 10.0, this Xʀ remains on iOS 12.3.1, etc, but maybe if people are indeed having battery life issues even on the iPhone 16 lineup... well, if those are solved later perhaps it’s time.

We’ll see how my iPhone 16 fares on whatever iOS version I receive.

 

[goldmac2006]

You know, I’ve always struggled with this. I know I’ll never update to any major version... but do I stay on, say, 18.4 on the iPhone 16 or do I update to iOS 18.7 or 18.8? Perhaps, for long-term use, those are better.

So far, I’ve never hit the update button, so my 6s remains on iOS 10.0, this Xʀ remains on iOS 12.3.1, etc, but maybe if people are indeed having battery life issues even on the iPhone 16 lineup... well, if those are solved later perhaps it’s time.

We’ll see how my iPhone 16 fares on whatever iOS version I receive.

You block OTA updates on your iPhones, right?

 

[FeliApple]

Is this another reason why some users are still using iOS 17.7.4? I noticed a few iPhone users in the iOS beta threads mentioning battery life as a reason for their continued use.

Very likely. I’ve gone for the extreme path: never update anything and battery life will never be an issue.

When compatibility becomes an issue, upgrade the device and repeat the process, which is exactly what I’m doing.

Others push devices, but not to their absolute limit: when they see iOS updates start threatening their number, they stop. What do I mean by this? Well, if you need 6 hours of SOT, maybe iOS 12 gives 12. iOS 15 gives 10. iOS 16 is bad, and that plummets it to 7. Now you stop, because iOS 17 or 18 may break that threshold and it might threaten your usability.

Most don’t care, update anything as far as it goes, and then upgrade when the device is fully obliterated. It depends.

 

[FeliApple]

You block OTA updates on your iPhones, right?

I don’t do anything. I just ignore them. Eventually, iOS won’t even let you update via OTA:

 

[Artemiz]

You know, I’ve always struggled with this. I know I’ll never update to any major version... but do I stay on, say, 18.4 on the iPhone 16 or do I update to iOS 18.7 or 18.8? Perhaps, for long-term use, those are better.

So far, I’ve never hit the update button, so my 6s remains on iOS 10.0, this Xʀ remains on iOS 12.3.1, etc, but maybe if people are indeed having battery life issues even on the iPhone 16 lineup... well, if those are solved later perhaps it’s time.

We’ll see how my iPhone 16 fares on whatever iOS version I receive.

Most feature implementations stop by .5 so everything you see after that is refinements with minute changes. Any major features at that point would be pushed to the next major iOS.

An x.7.1 is definitely much more optimized than x.3.1. It’s still software so it’s neither perfect nor complete but refined enough to the level of Apple’s satisfaction.

 

[goldmac2006]

Very likely. I’ve gone for the extreme path: never update anything and battery life will never be an issue.

When compatibility becomes an issue, upgrade the device and repeat the process, which is exactly what I’m doing.

Others push devices, but not to their absolute limit: when they see iOS updates start threatening their number, they stop. What do I mean by this? Well, if you need 6 hours of SOT, maybe iOS 12 gives 12. iOS 15 gives 10. iOS 16 is bad, and that plummets it to 7. Now you stop, because iOS 17 or 18 may break that threshold and it might threaten your usability.

Most don’t care, update anything as far as it goes, and then upgrade when the device is fully obliterated. It depends.

Yeah, if an iPhone is still compatible with the latest iOS version, it’s still your decision whether to keep it at that specific iOS version, even if Apple stops signing it. I only do this when I have to resort to hacks on the iPhone XR to give it Apple intelligence as an incompatible device. But you have automatic updates off

 

[FeliApple]

Most feature implementations stop by .5 so everything you see after that is refinements with minute changes. Any major features at that point would be pushed to the next major iOS.

An x.7.1 is definitely much more optimized than x.3.1. It’s still software so it’s neither perfect nor complete but refined enough to the level of Apple’s satisfaction.

Yeah, but I’ve always seen updates as risk. What if I have a weird bug after an update? What if I can’t solve it? So ignore there aren’t any problems I probably won’t risk it.

Case in point: my last willing update was to iOS 7. An iPad 4. Well, the Game Center app kept crashing. Nothing I did ever fixed it. It crashed for nobody but me.

So I’m not risking stuff like that, if (and only if) mine works properly.

So if battery life suffers with the 16, I’ll consider it. Otherwise I won’t, even if people report improved battery life.

My expectations are simple: with my usage, it must be better than this Xʀ on iOS 12.

 

[FeliApple]

Yeah, if an iPhone is still compatible with the latest iOS version, it’s still your decision whether to keep it at that specific iOS version, even if Apple stops signing it. I only do this when I have to resort to hacks on the iPhone XR to give it Apple intelligence as an incompatible device. But you have automatic updates off

Yeah, I’m not interested in features. I want performance and battery life over everything else. If I have to sacrifice any and all features, so be it.

 

[Artemiz]

Yeah, but I’ve always seen updates as risk. What if I have a weird bug after an update? What if I can’t solve it? So ignore there aren’t any problems I probably won’t risk it.

If you’re planning on keeping the device on that specific iOS version then my suggestion would be to stop updating once you’ve found the update that’s to your satisfaction. It could be .2 or .3.1.

Then reset and set it up as new when they release x.7 version. Update only to point updates after that.

 

[FeliApple]

If you’re planning on keeping the device on that specific iOS version then my suggestion would be to stop updating once you’ve found the update that’s to your satisfaction. It could be .2 or .3.1.

Then reset and set it up as new when they release x.7 version. Update only to point updates after that.

That .7 is still risky, assuming everything is fine and the iPhone 16 performs to my standards on, say, iOS 18.4.

We’ll see, I’m saying this because I’m assuming I may have the same battery life problems as everyone else, even with my optimisation patterns.

 

[Artemiz]

That .7 is still risky, assuming everything is fine and the iPhone 16 performs to my standards on, say, iOS 18.4.

You’re welcome to leave it at 18.4 if you luck out and you’re not concerned about security updates. But the way it works, 18.7 would be much more refined than 18.4.

It’s just a fact of SDLC.

 

[FeliApple]

You’re welcome to leave it at 18.4 if you luck out and you’re not concerned about security updates. But the way it works, 18.7 would be much more refined than 18.4.

It’s just a fact of SDLC.

Just for reference, I expect at least this battery life:

5 hours of SOT, 100-70%.

 

[Artemiz]

Just for reference, I expect at least this battery life:

5 hours of SOT, 100-70%.View attachment 2482939

If Safari and Reddit are at the top then you might be seeing better battery life than other folks here.
You may not benefit much from LPM since unlike Xr the 16s can automatically drop down to 1Hz on static screens. So try it both with and without.

Pro tip: You might benefit from Dark mode on 16s due to OLED and charge limit to 80% to maximize battery health.

 

[FeliApple]

If Safari and Reddit are at the top then you might be seeing better battery life than other folks here.
You may not benefit much from LPM since unlike Xr the 16s can automatically drop down to 1Hz on static screens. So try it both with and without.

Pro tip: You might benefit from Dark mode on 16s due to OLED and charge limit to 80% to maximize battery health.

Yeah, like I said, I don’t expect people to match my battery life (I have efficient settings, low brightness, light usage, and LPM), but the numbers I’m seeing are too low. 33% of spec is too low, people used to be closer to 50%.

Like I said, my expectation is one: be better than the Xʀ with the same settings and usage. I’ll tell you next month.

As for LPM... frankly, I use it out of habit. I’ve tried it zero times on my Xʀ. But back when iOS 9 was the latest device, I did compare my iPhone 6s with and without LPM and there was no perceivable difference. The Xʀ is basically six years in and I have always used it like this, I’m not changing it now. I’ll run some tests with the 16, though.

I will probably use dark mode, but I will not be using any type of charge limit.

I have a 5.5-year-old iPhone Xʀ. It has always been charged to 100%. It has 89% battery health, and, due to being on iOS 12, I get the exact same battery life I got back when it was new. Truth is, I don’t need to conserve battery health, even if limiting my battery life would help, I’m not interested.

So I’ll run to 100%, with efficient settings, and I’ll let you know how it goes. At a minimum, like I said, I want it to be better than this Xʀ.

 

[goldmac2006]

Just for reference, I expect at least this battery life:

5 hours of SOT, 100-70%.View attachment 2482939

24/7 low power mode? Don’t overdo it it’s still going to slow down your iPhone for the most part. It’s due to the background processes being suspended or lowered.

 

[FeliApple]

24/7 low power mode? Don’t overdo it it’s still going to slow down your iPhone for the most part. It’s due to the background processes being suspended or lowered.

Background app refresh has been fully disabled since my first iPhone anyway, it’s not worth the battery drain.

The iPhone Xʀ is ridiculously fast on iOS 12. Apple optimised iOS 12 for speed and it shows.

A simple example: the finger gesture on Safari on Macrumors to go back? It’s instant.

A reload takes pretty much no time. Notes takes... what? 0.3 seconds to open? Maybe it’s even faster.

Yes, iOS 12 on the A12 Bionic is THAT smooth. Honestly, I doubt the iPhone 16 on iOS 18 can match this Xʀ for sheer speed, it’ll be an interesting thing to pay attention to.

Imagine if this upgrade were to actually be a downgrade!!!

 

[kirbysmartsdawg]

Just for reference, I expect at least this battery life:

5 hours of SOT, 100-70%.View attachment 2482939

If you are constantly using low power mode, none of you numbers truly count. That is not reality to run low power mode all the time.