iPhone 8 battery drain, perhaps with iOS 14

This is a persistent topic but our two iPhone 8s have started discharging at a high rate, possibly after updating to iOS 14 (now on 14.7.1 with no improvement).
This morning mine was fully charged and 4 hours later it has dropped to 70% after very little use. “Battery health” is 91%. We both have Apple Watches and I read somewhere that people are experiencing high iPhone battery drain when they have a Watch paired but haven’t been able to confirm this.
One possible factor is that the Battery app reports average Screen On of 1hr 15min and Screen Off of only 7min. Does this mean when the screen is off but the phone is not sleeping?
That same app has no unusual app usage over the last 10 days (top is Phone at 26%, then Home & Lock Screen 17% then Messages 7%). I have read that Podcasts has been causing battery drain without showing up in the Battery app usage but this doesn’t seem to be my problem (I deleted the app and am still experiencing high discharge).
Most discussions on other websites seem resigned to waiting for Apple to recognise there is a problem and issue a fix!
Update: both phones had wifi calling set to “on”. I have turned it off - just in case that is causing battery drain.

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I have a refurbished original iPhone SE here, and the battery health is also 91%. The biggest power usage on my phone is the Covid-19 Exposure Notification, and my phone has typically lasted about a day before needing to be plugged in to charge again.

What is your auto-lock setting (under Display & Brightness)? Also, do you have Bluetooth enabled?

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A few random thoughts…

  • Have you tried powering the iPhones off and back on, just to make sure they have a clean start on everything?

  • How old are the batteries (ie, are they original, and when did you purchase)? 91% feels pretty low to me, but I’ve never seen a good indication of what percentages match with what sort of daily battery life.

  • Have you changed the Peak Performance settings such that iOS might not be able to optimize as it wants?

Similar to you and @tidbits33 I also have 92%, but this in on a not even 1-year old 12 mini with, in general, great battery life. All I’m saying here is that I wouldn’t necessarily assume 91% battery health means you’re going to have to expect a hit on battery life. In your case I would indeed assume it’s related to activity. Of course different iPhones have different batteries, and they might very well behave differently.

That’s fascinating. My nearly 2-year-old iPhone 11 Pro has 100% Maximum Capacity.

Obviously, people use their iPhones in very different ways and in very different environments, but I wonder how that number is calculated.

I had the battery on my 8+ replaced a few months ago. After reading the information here, I’ve noticed the battery is burning up faster, as Michael noticed, though I don’t have a watch. This is extremely aggravating.

Thank you everyone.

I have tried turning both phones off then on - no change to drain

Mine was purchased in November 2019 and is covered by Applecare until November this year. My understanding is that Apple won’t replace the battery until it drops to less than 80% ( looks like I won’t meet that target by then - what a clever design!)

I have checked several optimisation tips. My issue is that the battery discharges relatively quickly when it is sitting there asleep. So it seems something that consumes power is running in the background but it doesn’t show up in the Battery Usage list.

I do have Bluetooth turned on all the time (paired with my watch). I suppose I could try turning that off for troubleshooting purposes. If it is this then it likely has something to do with recent OS updates.

I turned wifi (cell phone) calling off yesterday evening and the discharge rate still seems to be on the same trajectory this morning.

It’s not the Covid app. Much to my frustration we don’t have a Covid app operating in Australia. The government paid $6 million last year for an app that didn’t work in a practical way on iPhones. No sign of an update that uses the Apple/Android API.

I’ve experienced exactly that myself after a previous 14.x update. Restarting phone did not help. What eventually got it to go away was installing the 14.x+1 update. Very unpleasant experience because you realize it’s entirely out of your control and there’s nothing in Apple’s release notes that would give any indication. And of course without any rollback opportunity it’s essentially a gamble anyway I’m afraid.

My iPhone X (3-ish years old, 14.7.1) dinged me recently to tell me that my battery was significantly degraded. Per the Battery Health setting, the battery is at 87% max capacity, and I should replace it. I haven’t because even though I use the phone all through the day, by day’s end, the phone nearly always has 40% or more charge left. I’d probably upgrade the phone before spending the money on a new battery.

I have an Apple Watch paired to this phone, but looking at the Battery Usage by App, seems like the “Find My” is the biggest memory drainer for the least amount of interaction. But not unreasonable so as to drain my battery by day’s end.

What about backing up to iCloud (or the Mac, with encryption on so you don’t lose some sensitive things), doing an Erase All Content and Settings, and then restoring from backup? It takes some time but is easy to do.

Good suggestion - I will try that this evening (it’s morning here)
Update: I need to check things like unpairing the Apple Watch, disabling Find My etc before backing up then erasing the iPhone:

( that Support page is for swapping to a new phone but it seems to apply to resetting an iPhone and restoring from the backup)

You’ll definitely need to turn off Find My, but I’m not sure you need need to unpair the Apple Watch, since it will be the same phone afterward.

Since both our phones are suffering this annoyance I decided to try a few experiments to isolate the cause before doing a reset.
Yesterday I turned on Low Power Mode on my phone - no obvious change.
Today I will turn off wifi on my phone.
Update: That was interesting - the discharge with wifi off was about half that with it on. I have no idea what processes might be using so much wifi.

My iPhone 8 Plus started doing this a few weeks ago too. Down to 20% by lunchtime, even though the use was the same the previous day. Normally it would be more than 20% at the end of a day.

My battery health is 88%, which I figure is not bad for a phone that’s coming up on 4 years old.

But something changed recently that I’m not aware of that has drastically affected battery life.

Similar experiences here over the past month or so with an iPhone 7: I’ll go to sleep with the battery at around 93% and wake up to find it around 70%. Yesterday I checked the phone around 3:00 with a reading of 54%, and around 8:00 I had a low power warning and only 2% charge.

The battery drain is definitely associated with wifi. This snapshot of the Battery settings shows (from midway across) discharge with wifi off then, after lunch, the wifi on. The graph is much steeper with wifi on.


The start of the graph is also with wifi on, then it moves to charging at night.

My guess is that 14.xx introduced some background activity whenever connected to wifi. Maybe artwork for music or similar unwanted downloads is active? I don’t use iCloud for photos or backups so it can’t be that. I do have an Apple TV and Homepods so handshaking with them is a possibility.

I feel like giving Feedback to Apple suggesting that they look at this discussion!

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Based on what you’ve shown, I suspect some app on your phone is making lots of network use when WiFi is connected, but refrains when WiFi is turned off, perhaps because it requires permission to do the same over a cellular connection. But if that were the case, I’m sure the culprit would be appearing in the Energy Usage chart under Settings > Battery. I’d be very surprised if any system services were using that much network data!

I’ve seen occasional heavy drain on both iPad and iPhone. Looking at the Battery preference, it seems the App Store was running (even though I didn’t launch it) and chewing up the battery. I don’t have a lot of apps (compared to other people) on my phone. Pad but not Phone are set for auto updating.

It -feels- as if App Store is doing background processing and possibly updating of the system stuff, but I have no idea if that is the case. (iPhone 12 Pro, 2020 iPad)

I’ve seen this before and, for me, turning off Settings / App Store / Video Autoplay seemed to fix that battery issue. If I reset my phone and set up as scratch, that’s one of my steps when I set up the new phone.

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“autoplay” as a default is evil in all cases! (But on my phone at least this is off. We’ll see if I get a reccurance of the App Store drain.)