iOS 14.7 Battery Drain

I'm not ruling out a battery drain problem, but you can't judge battery drain related to a new iOS version within a day of the installation. Every update has some housekeeping to do (varies by update) which takes a lot of cpu time and thus a lot of battery draw, and generates heat. Variables include what needs to be done and how much stuff is on your phone. For example, an update with only some security fixes may only need a few minutes to do its after update chores, while the update a few years ago that changed how each photo was stored and indexed took many hours on a phone with a lot of photos.

For this 14.7 update, on my old iPhone 7 with little on it, it used close to 100% cpu time for several hours and got quite warm. But the next day it was fine. My iPhone 11 went quite a bit faster and also was fine the next day. I didn't try to run from the battery or draw any conclusions about battery draw (or performance, since a lot of cpu usage elsewhere can make the phone feel sluggish) until at least the next day.

When I do updates, I take the case off so heat can dissipate better, insure the battery is fully charged, back up the phone, reboot the phone, then with the phone plugged into a charging block, do the update and then leave it connected to the charger until the phone has cooled down to room temperature for at least a few hours, and then keep it on the charger as much as I can for the next 24 hours.

Protect & Prolong the life of your iPhone's Battery: Batteries - Maximising Performance - Apple (IN)

Try some of these options too.

1. Avoid Screen Mirroring
2. Put on Low Power Mode
3. Put Auto-Lock on (1 min):- with low power mode it will be 30 Sec
4. Put Auto Answer Off
5. Disable Push notifications for apps you do not use often
6. Keep your iPhone Facedown to prevent notifications to light up the screen
7. Enable Auto-Brightness:- Settings > General > Accessibility > Display Accommodations > Auto-Brightness [Enable]
8. Manually lower brightness from Control Center
9. If you Want to watch continuous Video. Stream it on TV or a Monitor
10. Don't force close apps; Apps that are not on the frontend screen are paused by the system to save energy. Apps require more energy to re-launch. Apps that are open in the background use large memory is a myth and quitting them is counterproductive
11. Location services to be allowed only while using the app
12. Set your iPhone to fetch email and calendar data from the internet less frequently
13. Turning off Background App Refresh 
14. Charge before it drops below 20-30%
15. Try connecting to trusted Wifi wherever available instead of Cellular
16. Enable Airplane mode in areas with bad cellular and wifi coverage. Your phone keeps trying for reconnection with the missing/weak network. This uses a lot of energy
17. Switch off Wifi & Bluetooth while in Roaming or Not in Range
18. Enable "Wifi Assist" : Settings > Cellular or Settings > Mobile Data > Wi-Fi Assist [Enable]
19. Periodically Check the Battery Health (Settings > Battery > Battery Health)

I updated to 14.7 yesterday and the phone had a high CPU usage after the update and the phone got warm (as is normal), but it went on for longer than the last several updates. It may have been as long as several hours. But this morning it's fine, low CPU usage and the phone is cool. No excess battery drain from high CPU usage.

As per all updates, give the phone 24 hours before you make any determination of possible changes in battery drain and life.

Here is an update: when FaceTime is turned off battery consumption is very low however when it is on it goes down rapidly. I suggest you guys try this and share. Also this might be a clue for the ios developers…

I had a battery drain issue with iOS 14.6. When I was away visiting family I noticed that the battery drain issue vanished. I think it was the wi-fi syncing between iTunes on my iMac and my iPhone that was causing the issue (there was a lot of network traffic). I disabled that in iTunes and removed the option to see my iPhone in iTunes and Finder and all was fixed.

Sadly I can't post direct instructions given that now I've fixed the problem I can't replicated the steps, but hopefully that gives folk something to try. Try downloading Wireshark (google will find it) to see if there is a lot of network traffic between your phone and imac.

apple releases ios 14.7.1 install it may be it will fix that issue

I haven't every experienced a battery drain except the first hours or day after an update, so I don't have any personal experience to share. Some of the things I've read on line include misbehaving apps (either benign or malicious), or something that gets messed up in memory for the operating system, so only after a day would I probably next try a power down, wait 60 seconds, then power back up. If the drain continues, check settings to see if it can identify an app that's drawing a lot. Perhaps there's an app that somehow conflicts with the new iOS version.

Something else that I do is prior to an iOS update is to update all my apps, and then shortly after the update also update all my apps.

There's probably more suggestions on troubleshooting online, or the next thing would be to check with Apple.

Side note -- I wouldn't rule out a problem in iOS, but being a software profession for the past 36 years, if it was purely an iOS problem, even if only on some iPhone models, I'd expect to see a lot more people with problems. So my personal feeling is that it's more complicated than just the OS.

if you just update your device tomorrow then you should wait to settle down or reindexing it my take 2 days and after 2 days it may be shows normal usage and not heating issue

You’re fortunate that your battery was fine on 14.7, which is still signed. I’d go back before Apple unsigns it. You can always upgrade.

I updated my iphone 8 to ios 14.7 yesterday. Today I noticed my battery draining at record speeds. Then it stayed at 1% for over an hour but did not turn off. I suspected the battery display number was just wrong, so I turned my phone off and back on again. It was at 57% which is where it should have been. Then it started tanking again. So I think it is a bug in the indicator value and not actually using more battery.

I hope the right person at apple sees this and can use this information to fix the problem.

k_am_b -- This is a very interesting observation and possible problem description, and one that would be worthwhile for Apple to investigate.

Another related possibility could be that when there is a large current draw after an update (as I know there was after the 14.7 update on my iPhone 7 and my iPhone 11 Pro Max, due to high CPU usage percentage, a high load average value and a warm phone (very warm for the iPhone 7) for a while after the update, perhaps the circuitry and/or software that estimates remaining battery capacity only works well for lower current rates, and incorrectly calculates a faster drop in remaining capacity. Something else that would be worthwhile for the Apple engineers to check.

Either, or both of these, would help to explaining why people have seen large drops in displayed capacity right after an update.

Hi there. Have you restarted you phone after the update? My 14.7.1 is about 24 hours old so it’s too early to tell.

I’m not convinced that the battery will return to pre 14.5 vitality but here’s hope for improvement.

Also, if you have a problem still, you may be able to reinstall 14.7 if the version is still signed by Apple.

I know, right? I am seeing the same battery drain after upgrading to 14.7. This is the first time in many updates that I have seen a battery drain so at least this is not an continual issue with each update. I have the 11 Pro Max and I have all the settings off: Location, screen brightness all the way down, notifications off on most apps, which I don't have very many. Basically everything that they recommend people do to conserve battery life (at this point, with all the recommendations of conserving battery life, it seems almost ridiculous to even own a phone as they recommend you practically don't even use its functions to save battery from draining so quickly!).

My battery health is at 100% still, even after over one year of having it. That is impressive and this battery life is impressive and the best phone in the lineup I have owned. However, I am seeing the drain. It dropped from 85% to 75% in less than an hour and a half and I haven't even been using it and have no apps open nor am I using apps. I've been using my MacBook Pro M1 for everything today and not even touching the phone. So there is definitely a battery drain on the new 14.7 update.

I do hope that Apple comes out with a fix for this and this isn't the throttling I keep hearing about. I am hoping to have this phone for several more years before I update again. At the prices of phones these days on the rise, I can't keep affording a new device every year or two.

Same here. My 12 pro used to last all day with heavy use. Ever since iOS update 14.5 the battery drain has gotten worse.

14.7 is atrocious. 2 hours in only using safari with an ad blocker, no background apps open, and LTE only (no 5G) and down to 74%. Battery health is 99%.

I wish I could downgrade to 14.3.

Apple needs to get their bugs cleaned before sending out these battery killing updates.

I have this same problem after updating to 14.7.1. 14.7 was fine. New iphone, completely battery managed per every Mac IT suggestion. Great battery life until this update. Usually needed a charge every 3 days or so ONLY, with same behaviors. No social media apps installed or anything pulling data on my phone, with the exception of manual mail and some texts. Did a test with a 100% charged phone at 5am. Put Netflix on for 2 hours - normally fine (usually doesn't touch much battery life at all). Drained from 100% to 35% in 2 HOURS. I saw the drain on the battery life section and it's dramatic drop. Sigh. Is there anything to do about this?