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auxbuss

macrumors 6502
Original poster
Feb 18, 2014
453
329
UK
I don't use my phone much. It sits by my side barely touched for days on end. When using iOS 14, it used ~20% battery per day. After four days, at ~20% I'd recharge it. Life was easy.

iOS 15 stomped on that. iOS 15 uses ~33% per day. Here's the battery this morning. Charged at 13:00 on Wednesday, which by midday Thursday was at 66% with 33 minutes of use.

IMG_0270.png

What is using that much energy? Who knows? Who is using it overnight? Who knows?

So, this morning, I switched on Airplane Mode. The result:

IMG_0274.png

What is going on?

fwiw, I've already turned off Find My iPhone and System Customisation under Location Service/System Service because it was making so many location queries the indicator never turned off, and as a result draining the battery even faster.

Any ideas? And nope, I'm not holding it wrong.

Edit: In all cases, Bluetooth is off.
Edit 2: Battery health is 93%

Update: This is what happened overnight: 28%->6%. Phone left in Airplane mode:

IMG_0275.png
 
Last edited:

now i see it

macrumors G4
Jan 2, 2002
11,247
24,263
Low Power Mode can help alleviate idle drain too even when battery isn’t low.
But yes, I’ve experienced much higher idle battery drain on iOS 15 than iOS 14.
I’d say that iOS 15 is the worst iOS upgrade since iOS 9 (except for the early versions of iOS 10 that secretly throttled the phones). iOS 11 was pretty rough in the beginning too.
In fact they all pretty much suck until they get near their .6 release in the summer.
 

reppans

macrumors 6502
Dec 2, 2006
323
190
I updated from 14.8.1 to 15.3.1 last Sunday (I try to wait til version .3 or .4 of major IOS updates, based on all the horror stories). Got lucky - seems to have no impact on my batt life.

51889273984_e88d1981e6_o.jpg
 
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BigDO

macrumors 65816
Dec 9, 2012
1,352
2,118
Low Power Mode can help alleviate idle drain too even when battery isn’t low.
But yes, I’ve experienced much higher idle battery drain on iOS 15 than iOS 14.
I’d say that iOS 15 is the worst iOS upgrade since iOS 9 (except for the early versions of iOS 10 that secretly throttled the phones). iOS 11 was pretty rough in the beginning too.
In fact they all pretty much suck until they get near their .6 release in the summer.

Completely the opposite for me. iOS 15 has been very solid from 15.1 onwards.
 

auxbuss

macrumors 6502
Original poster
Feb 18, 2014
453
329
UK
I added an additional data point showing overnight behaviour.

Additional point from observation: this behaviour seems not to affect those who make a great deal more use of their phones.

Anyway, my question is about how one might diagnose this rather than counter-examples, which are lovely but don't help with the issue itself.
 
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Andrew73875

macrumors regular
Feb 1, 2022
225
599
I've updated to iOS 15 and also didn't have any battery issues.

What is your iPhone model? Maybe it's still indexing photos and other things? (due to the OCR feature)

Did you try force restart?

 
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Taz Mangus

macrumors 604
Mar 10, 2011
7,815
3,504
I added an additional data point showing overnight behaviour.

Additional point from observation: this behaviour seems not to affect those who make a great deal more use of their phones.

Anyway, my question is about how one might diagnose this rather than counter-examples, which are lovely but don't help with the issue itself.
One approach would be to do a backup of your phone to your computer or iCloud, put your phone into Recovery Mode and do a Restore and Update. This will erase the complete contents of the phone, download and install the latest version of iOS to your phone. Setup your phone as a new device, don't restore from backup. Leave the phone in factory setup condition. Leave it this way for maybe 2 days. See if the battery life is still bad. Do an Erase All Contents, restore from backup. See how the battery life is after restoring from backup.
 
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CTHarrryH

macrumors 68030
Jul 4, 2012
2,967
1,482
Don't have that problem. The screen shots don't show if any application (or system services) are using power? What I have found since 15.x is that SIRI is my biggest user even though I don't use SIRI
 
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JM

macrumors 601
Nov 23, 2014
4,086
6,381
Don't have that problem. The screen shots don't show if any application (or system services) are using power? What I have found since 15.x is that SIRI is my biggest user even though I don't use SIRI
Siri is a vampire. Silent and sucks the juice out of the battery.

I have 13 mini on Verizon with 15.3.1 with no ultra wide band plan (so just regular 4g/5g lameness).

I got Siri issues, too. Showing up too high in the percentage used, but after a hookup to iTunes, save backup to computer, on phone erase all contents and settings, then setup the phone using that iTunes backup, the Siri issue went away, and it used 4% in the last ten days… not bad when I have all Siri settings for Only Apple Apps set to ON to test how bad the battery usage really is.

I don’t have the standby drain problem when I’m on Wi-Fi…. But when I’m on cellular 4g/5g, it is maybe twice as much battery usage overall. My theory is the 5g chip in the 13 isn’t as battery friendly as they say it is…. So I’m wondering if the OP has their battery drain on standby on cell service and not Wi-Fi?
 

auxbuss

macrumors 6502
Original poster
Feb 18, 2014
453
329
UK
Don't have that problem. The screen shots don't show if any application (or system services) are using power? What I have found since 15.x is that SIRI is my biggest user even though I don't use SIRI
Siri is switched off.

I'm not using any apps. As I said, the phone is just sitting by my side (almost) unused. fyi: the top apps are Home & Lock Screen, and Settings (because all I'm doing is going in to Battery to take the snapshots).
 
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auxbuss

macrumors 6502
Original poster
Feb 18, 2014
453
329
UK
To reiterate: when using iOS 14, the phone used ~20% battery per day. The update to iOS 15.3 (and subsequently 15.3.1) increased that to ~33% per day. No change in behaviour. No change in apps. Same phone, same setup.

The question I asked is: what is the cause?
 

auxbuss

macrumors 6502
Original poster
Feb 18, 2014
453
329
UK
I don’t have the standby drain problem when I’m on Wi-Fi…. But when I’m on cellular 4g/5g, it is maybe twice as much battery usage overall. My theory is the 5g chip in the 13 isn’t as battery friendly as they say it is…. So I’m wondering if the OP has their battery drain on standby on cell service and not Wi-Fi?
I have Mobile Data and Wireless switched on – as I always have. But clearly the phone is using wireless, since it's only a few metres from the router. I'm on 4G.

I will switch off Mobile Data today to see if this has any effect. However, as shown above, when in Airplane mode very little power was used until, suddenly, it virtually drained the battery overnight, while still in Airplane mode.
 

Taz Mangus

macrumors 604
Mar 10, 2011
7,815
3,504
My suggestion, do a Recovery Mode Restore. This will erase the entire flash on the phone and install a fresh copy of latest version of iOS. Setup the phone as a new device. Try that and see if the battery life improves.
 

JM

macrumors 601
Nov 23, 2014
4,086
6,381
I have Mobile Data and Wireless switched on – as I always have. But clearly the phone is using wireless, since it's only a few metres from the router. I'm on 4G.

I will switch off Mobile Data today to see if this has any effect. However, as shown above, when in Airplane mode very little power was used until, suddenly, it virtually drained the battery overnight, while still in Airplane mode.
Okay yeah thank you. That makes no sense with airplane on that it drains.

Draining with airplane mode “shouldn’t” happen :(

I read on a thread somewhere that I had a lot of logs on my phone that build up, and after connecting to iTunes it dumps them. Also the backup to iTunes: then restore from that backup: seems to reset my phone’s bad behavior.

You “should” not lose any photos or anything when you backup to iTunes (make sure you do ENCRYPTED backup to save cards and health data, etc.!)

When you restore from that backup, everything should be there exactly as before, just have to wait for all the non-Apple apps to download again.

Good luck!!

*important note: make sure to have the most recent iOS version installed on your phone BEFORE the backup. Because when you try to restore from that backup, iPhone will only let you restore from current iOS version. If you backup an older version of iOS, and then try to restore, it will tell you you can’t and have to update to latest version of iOS. That’s what happened to me a few years ago, anyways. And I lost my data forever.
 

JM

macrumors 601
Nov 23, 2014
4,086
6,381
Low Power Mode can help alleviate idle drain too even when battery isn’t low.
But yes, I’ve experienced much higher idle battery drain on iOS 15 than iOS 14.
I’d say that iOS 15 is the worst iOS upgrade since iOS 9 (except for the early versions of iOS 10 that secretly throttled the phones). iOS 11 was pretty rough in the beginning too.
In fact they all pretty much suck until they get near their .6 release in the summer.
You might be the only other person I’ve read on here that remembers and said anything about how bad iOS 9 was ?

iOS 15 as bad as it is, it doesn’t hold a candle to iOS 9 ?
 

wallenium

macrumors newbie
Sep 26, 2016
12
9
BE89CE70-6E96-44DC-B2E0-87A4585C7692.jpeg
Same problem here.
I detected, that home app is usk g 82% of my battery and causing a high load.
There seems to be an issue with thread implementation, hammering the AppleTV with thread dns requests..


Or on reddit
https://www.reddit.com/r/HomePod/comments/rrepay
Seems that there is a major issue, happening on some setups only… maybe caused by a bug together with UniFi hardware? Not sure.
Startet with iOS 15… 14.x did well.

Yesterday, my battery died within 3 hours…
 

w5jck

Suspended
Nov 9, 2013
1,516
1,934
Just FYI my iPhone 13 Pro Max is using about the same amount of battery per day under iOS 15.3.1 as it did under iOS 14.x.y. But I have the enable Wi-Fi for calls turned on which helps. However, my iPad Air 2020 is draining the battery much quicker under iPadOS 15.3.1 than it did under iPadOS 14.x.y. iPadOS 15 seems to be much worse off over all than iOS 15 concerning bugs and issues.

You might check which, if any, widgets you have running. Some of those phone home a lot.

You might also check which apps are using location services. Most don't need it, period! Those that do, I tend to set the permissions to use use it to "only when app is open". Otherwise location services can drain a lot of battery.

My main battery drainers on the iPhone 13 Pro Max are phone calls @ 26%, Music app @ 22%, with a few apps around 5% to 6% but most at or below 2%. But I keep Siri turned off and rarely use Safari on the iPhone 13 Pro Max as I prefer to use my iPad Air 2020 for web surfing.
 

OhMyMy

Suspended
Oct 21, 2021
986
1,310
Just FYI my iPhone 13 Pro Max is using about the same amount of battery per day under iOS 15.3.1 as it did under iOS 14.x.y. But I have the enable Wi-Fi for calls turned on which helps. However, my iPad Air 2020 is draining the battery much quicker under iPadOS 15.3.1 than it did under iPadOS 14.x.y. iPadOS 15 seems to be much worse off over all than iOS 15 concerning bugs and issues.

You might check which, if any, widgets you have running. Some of those phone home a lot.

You might also check which apps are using location services. Most don't need it, period! Those that do, I tend to set the permissions to use use it to "only when app is open". Otherwise location services can drain a lot of battery.

My main battery drainers on the iPhone 13 Pro Max are phone calls @ 26%, Music app @ 22%, with a few apps around 5% to 6% but most at or below 2%. But I keep Siri turned off and rarely use Safari on the iPhone 13 Pro Max as I prefer to use my iPad Air 2020 for web surfing.
13 Pro Max came with iOS 15. How could you have iOS 14.x on a device released just a few months ago?
 

auxbuss

macrumors 6502
Original poster
Feb 18, 2014
453
329
UK
My suggestion, do a Recovery Mode Restore. This will erase the entire flash on the phone and install a fresh copy of latest version of iOS. Setup the phone as a new device. Try that and see if the battery life improves.
Yes. This seems like an inevitable step now.
 

auxbuss

macrumors 6502
Original poster
Feb 18, 2014
453
329
UK
Draining with airplane mode “shouldn’t” happen :(

I read on a thread somewhere that I had a lot of logs on my phone that build up, and after connecting to iTunes it dumps them. Also the backup to iTunes: then restore from that backup: seems to reset my phone’s bad behavior.
re: Airplane mode: Yes, I was surprised. I posted the result above to show it. As I say: what is going on?
 

auxbuss

macrumors 6502
Original poster
Feb 18, 2014
453
329
UK
You might check which, if any, widgets you have running. Some of those phone home a lot.

You might also check which apps are using location services. Most don't need it, period! Those that do, I tend to set the permissions to use use it to "only when app is open". Otherwise location services can drain a lot of battery.
No widgets. Almost all Location Services are off, now.
 

auxbuss

macrumors 6502
Original poster
Feb 18, 2014
453
329
UK
I have Mobile Data and Wireless switched on – as I always have. But clearly the phone is using wireless, since it's only a few metres from the router. I'm on 4G.

I will switch off Mobile Data today to see if this has any effect. However, as shown above, when in Airplane mode very little power was used until, suddenly, it virtually drained the battery overnight, while still in Airplane mode.
So, the result of this is interesting:

IMG_0277.png

69%-65% from 08:00 to 19:00 by switching off Mobile Data (no other changes). This is similar to the result of switching on Airplane Mode (see above), so I'll leave it overnight to see whether the massive drain while I'm sleeping occurs again.
 
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