Level 2

158 points

iPhone 12 battery draining fast

Hi all,

Trying to work out if I have a defective unit I need to send back or if there's a wider issue here. The iPhone 12 Pro is advertised as having a smaller battery than the iPhone 11 Pro so I expected to have slightly reduced battery life (which is fine as 11 Pro was excellent).

However I'm noticing that the iPhone 12 Pro is draining when idle with almost no background activity at a rate of 4% which is much faster than my previous iPhone 11 Pro, and to be honest a faster idle drain than I can actually remember from a new iPhone. First instinct was to disable Mobile data to see if it was a 5G thing, but I actually don't see any real difference from doing that (which makes sense as I've been on Wifi 98% of the time since I got it).

No matter what I try, it seems to be going down oddly quick. Not to an useable level or anything world ending, but I guess its sort of suspicious. I check the battery report, and it's not showing any real culprit, just a rapid decline for no clear reason.

If anyone can share their idle battery with either 12 or 12 Pro I'd really appreciate it.

[Re-Titled by Moderator]

iPhone 12 Pro, iOS 14

Posted on Oct 25, 2020 8:14 AM

Top-ranking reply

user0197

Level 2

172 points

Posted on Jan 1, 2021 5:25 AM

After a couple days of experimenting.

Let me give you scenarios/examples with no regard to any other settings other than those mentioned being turned on or off.

iPhone 12 Pro running iOS 14.3

SIM card installed, WiFi on, Cellular On, Bluetooth in Standby (Turned off in CC to disable new connections, but still enabled)

Battery drops between 15 and 30% over an eight hour time frame while not being in use. (This was the case for a couple days, until I realized something was clearly wrong)

SIM card installed, WiFi off, Cellular off, Bluetooth standby same as before

Battery drops around 10% over the same time frame (Better, but still not satisfying)

Now get this!

SIM card taken out, Wifi on, Cellular off, Bluetooth same as before, I also turned Airplane Mode on for the sake of it

Draining between 1 and 3% , over the span of 8 hours.

I know, it seems absolutely silly to use an iPhone without a SIM card, but as long as this bug is not fixed taking out the Sim card might be your best option to prevent your battery from draining over night. Or you just simply keep it on a charger. Keeping the SIM and at least turning off WiFi and cellular or putting the device into airplane mode should make the battery drain a little less too.

Some other things you might want to switch off, if only to test for a couple days to see if battery life improves and slows the drain. Keep in mind, you can disable everything temporarily and don't have to worry about anything breaking. If something needs a certain thing enabled, iOS will most likely give you a prompt anyways. You can go back and enable everything again, but until a version of iOS 14.3.x or 14.4 is released that addresses the those kind of issues, it's the best and to be frank, the only thing you can do.

Location Services > System Services. Be bold and turn off EVERYTHING. Toggle the status bar icon (the switch on the very bottom) so when you slowly enable them one by one again, you can keep an eye on what triggers the location to update. With the status bar icon on, you can check and investigate closely how and when a certain service is updating. I found the Find my iPhone location feature updates like crazy.

System customization also updates in the background constantly ( if you turn it off, Dark Mode/ Appearance will still be able to work in sunset/sunrise mode, night mode however will work only when you put it on a custom schedule, and optimized battery charging will not work (even the option itself in the battery menu is enabled) if you have Significant Location and/or System Customization disabled).

Put Bluetooth into standby so it stops searching for new devices (Toggle it via Control Center so the icon becomes white.)

Turn off 'Ask to Join Networks' and set 'Auto-join Hotspot' to Never in Wi-Fi settings to stop the device from constantly checking for sources, notifying you and trying to connect to other routers.

I don't mention any of those things like turning off Background App refresh, dimming your display etc as those can be found in literary every 'iPhone battery savings' video or article.

It is clear that the issue can be pinpointed to the cellular modem, which can only be put into completely pause if there is no SIM card in the device. Airplane mode alone does not seem to fix the issue fully nor does turning off Cellular data help much if anything.

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2,818 replies

Nov 28, 2020 7:34 AM in response to Bobby1983

I agree. It’s a carrier problem. My Telekom eSIM works fine, when switching to Vodafone physical sim I get the excessive drain. I will get a three SIM card next week replacing my Vodafone. I’m curious to see what this will do.

Nov 30, 2020 2:23 AM in response to 炸弹黑

I’m experiencing the same as you. Only in DSDS mode I get the excessive battery drain. Therefore there is definitely something wrong with the modem firmware.

But it seems the problem also occurs with people using only one line, possibly the issue is way more diversified. I believe though it’s just an iPhone 12 problem because of the new modem. I don’t think older iPhone, even running the same iOS version are affected.

Oziegit

Level 1

4 points

Nov 30, 2020 11:30 AM in response to Master26A

I sent mine back and reverted back to my trusty 11 Pro Max. I also expected a slightly less battery life, but not to the extent I experienced.

I kept mine for a week and did some benchmark tests alongside my 11 Pro Max - streaming, surfing and leaving idle.

On the streaming side I ran the same long film twice (Lord of the Rings) from my iTunes library (both fully charged) at the same time and the battery depletion was faster on the 12 than the 11.

After nearly 8 hours of constant streaming over my wifi the 12 was at 22% and the 11 was at 56%. Apple states you can get nearly 17 hours streaming on the 12 Pro Max.... so that was a fail.

Then did surfing and watching the odd clip on Facebook for an hour on both and again the 12 was poor, draining by 18%.

final test was leaving them both idle over night (all background apps closed) and when I checked in the morning (about 9 hours) and my 11 was on 96% and the 12 was on 63%.

I did give it 5 days before doing these tests, just ensuring all updates were completed and the phone did all it needed to do to settle bond with its new owner 🤣

i don’t know if mine was part of a bad batch (got mine the day it was released) or mine was put together quickly at the end of Friday afternoon. However, going by this chat room I would say I’m not the only one who had battery issues. I’ll try upgrading in 6 months, just in case there were bad batches released.

Dec 1, 2020 9:50 AM in response to Danyxp

I have been following this thread due to having the same issues.

After trying all of the fixes suggested, I can confirm 100% that after turning off my WiFi my battery drain has literally stopped.

I have timed it and after normal usage it has dropped only 2% in the last 50 minutes compared to an average of 9-10%.

Apple need to sort this out ASAP!

The support staff are useless and just telling customers everything is ok and working as expected.

Dec 1, 2020 1:00 PM in response to Danyxp

Nope, turning off the wifi didn’t fix it for long. It’s back at it again after few hours 😂

The only thing that reliably helped me was full airplane mode.

So I’m quite disappointed with the phone and the situation as a whole, and how Apple keeps quiet about it.

Sadly, I cannot return the phone anymore as I’m past two weeks period. But I’ll try anyway...

Dec 1, 2020 1:06 PM in response to viktor.ostapenko

I suspect people who saw an improvement when they turned off wi-fi have actually got another problem (like an app doing background updates that hasn't got permission to access mobile data) over and above the basic modem power drain which is the main problem being discussed here. For most people, turning off wi-fi makes no difference, but those who say they saw a difference when they did turn off wi-fi tended to have even higher power drain than the 3-4% an hour the rest of us are seeing, like the commenter above who was seeing 10% drain an hour.

This isn't a wi-fi problem; it's a cellular modem problem.

Dec 2, 2020 2:50 AM in response to matej.cer

For what it's worth, I sent mine back for a refund. It is too early to say for sure whether this is a silicon problem or a software problem, but both are certainly possible. The fact that some people have managed to get replacement handsets that don't show the problem points to silicon rather than software, but there are so many variables here (location, network, signal strength, other apps) that it is impossible to be sure.

If it is a silicon problem, I'm sure that Apple will do their best to produce a software fix for it, but that may not be possible, depending on the exact nature of the problem. Apple's continued silence is really not helpful for consumers here!

If you hang on to your handset, it is certainly not impossible that a software fix will appear in a future iOS update. But it is also not guaranteed. Which is why my 12 mini went back, I got my money back, and I will buy another one when and if this issue is reported as being fixed, which may be weeks or months away.

LVC1VS

Level 1

4 points

Dec 2, 2020 4:03 AM in response to Master26A

iPhone 12, Kyivstar (Ukraine). -30% over night in idle. Already replaced with another iPhone 12, but the problem is the same. Didn't test with other operators as I don't plan to change current one. I guess, I'll have to wait for iPhone 13, as 12 is obviously has some issues with it's modem.

johnj007

Level 1

9 points

Dec 3, 2020 5:24 PM in response to Master26A

I had the XS model for awhile before I traded to the 11 pro. I discovered that the battery drained quickly when optimized battery charge was turned on. When I turned it off the problem went away. Never figured out why...John

Dec 3, 2020 9:39 PM in response to 炸弹黑

After all my extensive testing it turns out that’s the same for me too. Clearly a dual sim standby issue.

not carrier related in my case. To me it means I can’t use the dual sim function, which is a little annoying as I’d always used this feature on my prior iPhones starting with the XS Max and never had problems. Apple support is no help unfortunately. So...I will carry two phones again...bummer!

Dec 3, 2020 10:21 PM in response to Tabi65

iPhone 12 discharge 25% per night. iPhone 12 mini - 30% per night. Reset network, device, restore from TM or setting like new NOT help. 14.2.1 not help. Last beta 3 14.3 discharge 24% tonight. Disable wifi or bt not help.

Dec 4, 2020 3:51 AM in response to Evgen_new

Update from 12/04/2020

Switching from 4G (LTE) to 3G in the settings did not completely solve the problem, but the battery consumption per night dropped to 5% in standby mode.

I will be testing with my cellular data disabled.

Dec 6, 2020 1:02 AM in response to Alexeytrance

5/12

8:55 100% (Wi-Fi)

11:35 100% (wifi)

19:55 87% (Cell, 20 min screen time)

22:55 85% (wifi, stand by)

01:40 83% (Wi-Fi, stand by)

6/12

9:40 77% (Wi-Fi, stand by)

only 20 min screen time.

No no good...it lose 1% at hour (more or less) without using it!

Swissxyz

Level 1

4 points

Dec 6, 2020 3:38 AM in response to Master26A

Please can we all have the time to fill this out:

https://www.apple.com/feedback/iphone.html

It looks like Apple hasn't acknowledge the issue (as of yet) and I think if we raise concerns regarding the matter, they'd probably look into it as a matter of urgency. It looks like all 12 series have been affected and not many users have noticed the issue.

Dec 6, 2020 4:41 AM in response to _bubble__trouble_

It is switching to 3G that helps reduce battery consumption from 20% to 5% per night, but does not completely solve the problem.

The problem is not with all operators, MegaFon (Moscow) has a problem, TELE2 seems to be no problem.

It is unclear if you and your husband have the same provider, but your husband has no problem. Why is that.

According to posts from this thread, the provider plays a role.

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iPhone 12 battery draining fast