Level 1

19 points

iPhone 12 abnormal battery drain / SHORT battery life

I bought iPhone 12 couple of weeks ago, and it didn't take me long to realize that the device is draining 20-30% each night (during a period of 7 hrs) on idle, which is very frustrating. I took it to the Genius Bar several days ago and the technicians there are perplexted and couldn't find the cause of the problem (no hardware issue). They offered a few suggestions (change a few settings) for me to test for the following days, and also offered to replace my device with a service unit, should the suggestions fail to solve the severe battery drain. I have been searching about this issue and found out that a lot of people (in USA, China and seemingly many other countries) are suffering from this excessive battery discharge issue with their brand new iPhone 12/12 Pro.

Below are some of the sugestive solutions I have collected, some of them given by Apple (non-working), and some of them given by iPhone users (some reported to be effective).

For the past few days I have been testing these solutions one by one night by night and here's what I got so far,

Turn off background app refresh (negligibly reduced battery drain)
Close all of the opened apps before sleep (negligibly reduced battery drain)
Update to IOS 14.2 (Not helpful)
Sign out iCould and sign in again (Not helpful)
Delete the built-in mail app (Not helpful)
Reset network settings (Not helpful)
Erase the iPhone and restore from a backup (Not helpful)
Charge the phone while sleeping (it's a workaround but NOT a fix)
Switch-off one of the two lines I'm using (will be tested today)
Use airplane mode before sleep (will be tested day after tmr)

Further, as you may already know, the battery graph shows nothing happened during the night (no apps no activity) and yet the battery drains 20-30 pct each night on idle.

In addition, I really don't think my iPhone 12's overal battery life is good enough, I am a LIGHT-moderate phone user, for example you may see from below last screenshot that I got a bit over 6 hours of screen-on time last Saturday and it consumed roughly 90 pct of battery, and that seems to be a best day for battery life efficiency, do you think it's nornal ? I think it is worse than the iPhone 11 and on-par with the iPhone SE 2020. So, I think, maybe the irregular battery drain of iPhone 12 consistantly exits during the whole day 24/7. And that is unacceptable.

Do let me know if you have the same issue or if you have found a workable solution.

iPhone 12, iOS 14

Posted on Nov 9, 2020 6:44 PM

Top-ranking reply

dexefd

Level 1

4 points

Posted on Dec 10, 2020 8:09 AM

I only tested single sim unfortunately.

In the test, some of them drain about 1.5~2.5% per hour with absolutely no activity. Also, connecting to WIFI does not improve the situation. In comparison, the normal units only drain about 0.3% per hour. They are all using the same content transferred from a preconfigured backup. Finally, Popping out the SIM on faulty units IMMEDIATELY solve the battery problem.

Hope this helps

View in context

Similar questions

25 replies

Deptors

Level 1

9 points

Nov 13, 2020 10:38 PM in response to 炸弹黑

Hi there! Switched off the second line on my device (mobile section) on your advice ... from 04 00am - 08 00am charge loss was 0% with all services turned off ! A little later it turned out that the charge is gone again ! I decided to make a full recovery as new without a backup : the result - from 10 00pm to 08 00 am the charge loss was 23% ((( All Hope for iOS 14.3 ( some people recommend changing the physical sim card ) what do you think 🤔? Probably that issue related with mobile carriers? Best regards Aleksandr

炸弹黑 Author

Level 1

19 points

Nov 13, 2020 10:50 PM in response to Deptors

Hi, You mean by turning off a line, your phone’s irregular battery discharge situation improved, but later re-appeared ?

For me, what I said and suspected stands, if I turn off one line, the battery discharge rate seems to be acceptable, if I keep both lines on, then the battery drains an extra of 2%-3% per hour, which is unacceptable.

Any other method won’t solve the problem, and I also suspect it is a compatibility issue between the current iOS system with the iPhone 12 modem or its chip, and I hope Apple can fix it with iOS 14.3

Dec 1, 2020 10:55 PM in response to 炸弹黑

Hi. I have the same problem with 12 and 12mini. 25-30% per night on idle.

Reset and recovery for TM not help, reset and setting like new not help, public beta 14.3 not help, 14.2.1 not help, energy save discharge faster 30-35% per night))). I hope that apple fix it in new beta and release 14.3.

dexefd

Level 1

4 points

Dec 8, 2020 5:00 PM in response to 炸弹黑

you are not alone.

This is likely to be a less pronounced hardware fault. Have your unit returned would solve this.

Personally i have tested a dozen brand new iphone 12 pro and max simultaneously , about 1/4 have such issue; they are all using the same configuration data and network carrier. I haven't found any software solution to the faulty ones.

炸弹黑 Author

Level 1

19 points

Dec 15, 2020 5:14 PM in response to hafz88

Hi there,

So I have updated ro iOS 14.3 yesterday at noon and I immediately switched to DSDS mode to test it out, it has been short of a day until now and it seems to me that the abnormally fast battery drain I experienced on DSDS mode has been greatly reduced (fingers crossed). Last night my phone lost 5 percent during the span of 7.5 idle hours. I used to lose 20-30 percent during the same period of time on idle. Frankly speaking, I still think the battery drain is a bit higher than it should be. I’ll give it a few more days to conduct more tests.

KoNic123

Level 1

4 points

Dec 17, 2020 8:38 PM in response to dexefd

I bought a US unit iPhone 12 Pro Max and it only has 1 sim slot. The battery drain rate is unacceptable like OP said, and I can confirm your finding about the SIM card.

As soon as I pop out the SIM card, battery drain rate is pretty much only 0%-1%/hr afterward. I can imagine if it has anything to do with the sim/cell service, a dual sim unit would have drained a lot.

dexefd

Level 1

4 points

Dec 18, 2020 7:55 AM in response to KoNic123

Just one tiny update with numbers; because I think few people have really tested realworld talk time before.

1.. I tested 4G VoLTE talk time on several units (same carrier, same sim card, same system config).

The battery usage is:

Faulty ones: 8-12% per hour

Normal ones: 3-5% per hour

2.. with iOS 14.3 update, Faulty units' standby battery drain is almost removed when connected to WiFi; However, little was changed when using cellular data (as high as 0.8-1.5% per hour with zero activity). Seem to me , this is more like cellular network data traffic reduction during standby, than solving the real issue (cellular module uses more power than normal ones).

Finally, iOS 14.3

Returning the units to apple is the only solution so far.

Deptors

Level 1

9 points

Nov 20, 2020 5:43 AM in response to 炸弹黑

Hi there ! What about iOS 14.2.1 ? Any comments?

炸弹黑 Author

Level 1

19 points

Nov 20, 2020 9:25 PM in response to Deptors

I just updated to iOS 14.2.1 this morning. Dual Sim battery drain is about 2.5 percent per hour on idle, still unacceptable.

I’ll wait for 14.3

Dec 1, 2020 10:56 PM in response to arthas2020

This thread has been closed by the system or the community team. You may vote for any posts you find helpful, or search the Community for additional answers.

iPhone 12 abnormal battery drain / SHORT battery life