iOS 14.2/14.3 battery drain bug!

So when you did a restore, you installed all the 3rd party apps again. Someone having this problem (I don't) needs to run it for 48 hours with no apps installed, just the factory stock device, to see if it is the phone or the 3rd party apps that is the issue.

Disabling the weather widget did not help. For me, the only solution to date is to engage the "Low Power Mode". It seems to do more than just to disable "Background App Refresh" and mail fetch, as I still have an enormous battery drain when I manually turn all the background features off. The LPM seems to also clock down the processor, as everything is less responsive and the apps behave way more sluggish. With the LPM, the runtime is similar to my "normal" run time before iOS 14. But alas, this is not the way things should be.. :(

Is it the first generation SE?

When there is a sudden drop like this, my first though is maybe you should do a battery calibration?!

In a case like this, I suspect the battery not even being that bad, but just giving out a false reading.

I had an iPhone 6s sitting on 1% for hours (percentage jumping around and dropping in large amounts instantly like in your example) and powering on multiple times after it has shut itself off due to the 'empty' battery which it shouldn't be able to if the battery reading would be accurate. After doing the following procedure, it worked a whole lot better. It still has the original battery with 84% health. Granted it is the 6s and really rather old already, and while it didn't improve overall battery life by much, doing the calibration fixed the erratic percentage drops and made the device a little bit more reliable because 'what you see is what you get' and not a plummeting battery meter that is lingering on 1% for hours.

To calibrate: (it is best do to this on the weekend when you are less likely do not have any place to be early in the day etc.)

1) Drain your device until it shuts off. Reboot or at least try to until it doesn't do so anymore (also do it by the hard reboot method, as sometimes the device boots whereas it wouldn't boot if only the power button is held).

2) Leave unplugged for a couple hours (overnight is best)

3) charge the device until full and then leave plugged in for at least two more hours.

4) unplug, then do the whole procedure one more time

Be vigilant about those steps as only performing them the right way, will actually give you any real and good result. Good Luck!

More importantly, have they done a full (clean) install through iTunes, as opposed to an update. Another poster indicated that with the clean install, their problem was solved. YMMV.

You may need to perform a DFU recovery as I've done.

14.4 solved battery draining problems and sluggish performance on an iPhoneXS and a Mini4.

It's not on the release notes of 14.4 beta yet.

https://developer.apple.com/documentation/ios-ipados-release-notes/ios-ipados-14_4-beta-release-notes/

Some people reported that rebooting iPhone will increase the percentage numbers drastically. If so, it's just a battery info issue and not draining actual battery. I hope that's the case but not sure.

My iPhone is currently fully charged. Can someone try rebooting the iPhone and share the result?

Once again, is it the iOS or is it a 3rd party app that doesn't work well with the iOS. Your experience doesn't prove either. Until someone is willing to do some diagnostics, as I suggested, it's all speculation.

I'm not sure why there is resistance to perform a simple diagnostics by running a factory stock configuration overnight and reporting the result. What's the point of coming here and asking for help, then ignore it? Or maybe someone has, found out their phone works fine without all those 3rd party apps, and doesn't want to admit that it's not 14.3 that is the problem. OTOH, if a factory stock phone still has a battery issue, I'll be the first to admit the iOS is at fault.

Yes I have had same trouble. Always do an update but just seen that my local app uses 59% of battery so have deleted it. It’s a pity as I like to keep informed locally but must consider it when it drains my battery anyway giving it a try!

This all began with an iPhone Xs and Mini4 (with LTE) upgraded to 14.3 and bang went the battery and terrible UI lag. They were basically unusable (see earlier posts). Yesterday with the Mini4 running Beta 14.4.2 I turned off Find My and signed outta iCloud entirely. Charged it up to 100%, left Wifi & LTE on and let it sit over night unplugged. 10 hours later it was at 82% (promising). I then signed into iCloud, turned everything off that uses iCloud and let it sit from 80% . 8 hour later it had dropped to 39%, better but no where near as well as 13 or even 14.1.

Next test, I've signed into iMessages, charged it back up to 100%, left Wifi and LTE on, we'll see what we get in the AM.

14.4 has not made any noticeable difference to my 12 Pro sadly. The device has had enough time to reindex etc, so I don't think it does get any better at this point.

If your carrier allows you to enable Wi-Fi-Calling you are lucky, as you can continue to use your device normally even with Airplane Mode on and as long as you are connected to Wi-Fi.

The only thing, and I mean really, the only thing that helped mitigate the issue for me so far is to enable Airplane Mode while I am at home (which is pretty much all the time, and I suppose it is the same with a lot of people nowadays).

Strangely enough, the last time I was out and about for about 2 or 3 hours while constantly being connected to Cellular on LTE and using the phone quite a lot in that time ([all streamed via Apple Music] 1hr music via Bluetooth in the car, 1hr music via headphones, and some minor other tasks) I lost only 1%! which is crazy. I had full bars the whole time while having mostly 3 in my home. My hair's on end about this because it just doesn't make any sense to me.

Does the cellular modem use so much more power if it has anything but a full 4 bar signal all the time? It would make sense if I had only 1 miserable bar of cell reception in my home but since I do have 3 which isn't that bad, and it didn't drain at all last time I was out and not on Wi-Fi, I can't wrap my head around it.

Do you have the option to enable Wi-Fi calling?

If yes, could you enable that and also enable airplane mode (any call/texts etc will come through don't worry)

It would interest me if it stops the battery drain on other devices as well, since it does work on my 12 Pro. That would at least mean, that it is definitely a software bug with iOS 14 that is affecting all devices and not a hardware defect of a certain series. iPhone 12 owners have already been suspecting a hardware defect of the modem or a faulty batch.

When did you update? In the last 24 Hours? You might only have to wait another day or two. Depending on what version you are coming from, the device may have to do some indexing which consumes more power. Hopefully it settles down in a couple days for you.

I found a post on MacRumors that recommended toggling Airplane mode on and off... it seems to be working for me? At least I've managed to unplug the phone and have it not immediately die...

resetting TO factory settings after a backup of course might work, for some devices it does for others not...

@Ricky - to expand on my removed post, I have been on 14.2 and 14.3 for a long time.

The battery drain is predominantly from built-in Apple apps, including Photos (behaving badly - background refresh on battery even though I forbid it), Messages (ditto), and Phone. Also Home & Lock Screen has greater draw than it used to, and I do not use widgets at all.

Not sure what's going on.

I've turned off optimized battery charging numerous times, reset the phone, and went as far as to blow it away, fresh-load/install iOS 14.3, and see how a clean phone worked for a couple days.

Battery draw - on an iPhone 11 Pro Max w/ 99% of new - is about 15-20% more severe than iOS 14.1.

(14.2 kept turning on optimized battery charging, so I can't comment/draw a direct comparison)

This issue - battery - has been echoed by friends with iPhone 12 and 12 Pro Max devices, as well.

We're all seasoned iPhone users with at least six generations of iPhones ourselves (my wife and I do "tick" and "tock" - we alternate years - so I actually have ten generations of iPhones in my house).