iPhone 12 battery draining fast

I've also found that 3G is the only thing helping with the battery drain.

my carrier network is already updated to 45.0 and the drain is still there unless I put on 3g.

it's probably to do something with the 4g/modem/iPhone.. does anyone think this can be fixed with a software update or is it a hardware fault? because this is my second iPhone 12.. went from 12 to 12 PM .. experiencing the same issue. but same carrier and physical sim card/ data restored from icloud.

The last one percent stays longer after you charge your phone. For example, if you charge it to 100% it will stay at that and if you charge it to 60%, that 60% will stay there for a long time. If you charge it, then wait for it to drop 1-2% and then keep it. You’ll see the drain come back. That last charge percent is quite poweful.😂

Hey so which device were you using before?? 12 pro have only 2000 something mah compared to most of other android devices which has around 4000 to 5000 mah that’s too low and 12pro have small battery life compared to 11pro

Night 6 Selected 4G, manually selected O2, connected to home wifi, mobile data off, background refresh off, low power mode on

15-12-20 22:00 battery 92%

16-12–20 09:09 battery 75%

Putting aside the battery issues, everything else is good. The hardware is ok I think, so won’t be returning, it’s such a pain to swap over and migrate banking apps etc. Looks like 14.3 probably won’t make any difference to battery situation for me, but not making it worse. Will update today.

Night 7 Belt & braces approach. Backed up to iCloud and my MBP, updated to iOS 14.3 today, no carrier update. Leave it manually selected on 4G, didn’t perform very well last night, draining 17% with 14.2.1 O2 setting 45.0

16-12-20 22:18 battery 93% left on 

17-12-20 09:00 battery 72%

iOS 14.3 no better for me 21% drain. Will manually select 3G and see how that goes tonight.

I've tried switching manually 3g and it was working for me.

I was having the same issues and immediately when i've switched to 3g the battery drain gone. You can check my comment above i've share a screenshots also what was happen.

Best Regards!

iPhone 12 Pro Max with 15%-25% overnight drain.

Last night I turned off WiFi, Mobile Data and Bluetooth and drain was 1%.

Seems to suggest this is a software issue so I guess we hold tight and wait for Apple to pull their finger out.

Exactly the same as mine. I have switched from OnePlus 6 too.. I was really happy in terms of battery with my OnePlus. Like you said even when connected to wifi a 1% battery drop would take almost 2.5 to 3 hours. But with this brand new iPhone 12 seems to drop within 5mins of usage(apps like twitter, i use most often). The problem with my device is, only when it is connected to wifi I see the battery drain happening quickly

Unhappy.. I am very sure Apple knows about the issue. Hope for a fix ASAP.

LTE...but does't matter.

No one should be messing with settings just to get a "little less" issue with battery or any problem on the phone.

THE ONLY THING THAT STOP'S BATTERY DRAIN, OVERNIGHT OR DURING THE DAY, IS AIRPLANE MODE, and of course that's not the solution.

Are you talking about Beta? I can confirm that 14.3 fixed the dual SIM standby issue for me. I‘m now in day 3 after update and enabling the second line again. Voila, no more excessive battery train. I‘m located in Germany eSIM Telekom physical SIM WindTre in roaming using o2 by default.

Also many thanks to Apple. They actually read this thread and contacting me for further information. That‘s what makes the difference, they do care about customer satisfaction. THANKS!

As I still have my 11 Pro Max, which is luckily not sold yet, I will restore it during this week-end and use it again during next week but I am pretty sure it will not handle like the 12 Pro Max. I will post some battery usage curves to allow every one to compare a normal iPhone and the 12 ;)

I also put a lot of hope in the 14.4 which seems to fix the issue according to a previous feedback in this thread.

No, this would suggest an issue with the modem itself, not software. When the modem is on in any way (WiFi, Bluetooth, mobile data), it causes excessive drain. When it is switched off, the iPhone has a much lighter drain.

The modem is clearly power-hungry and either Apple are aware of this and don’t care, or there is an issue with the modem which will require replacements but I guess Apple will wait for the issue to snowball in order for them to actually address the issue with either replacements or attempt to fix with a software update, though I doubt the latter is possible.

I'm still experiencing heavy battery drain on my 12 pro max. I switched off 5G and now the phone does not get as hot when charging (alway official Apple charger). But Im still experiencing 20% drain over 6-8 hour period without activity. Will bring it to Apple store in the next few days and we'll see what they say

Me too. Went from 33% last night down to 15% this morning...down to 3% by the afternoon. 12 Pro Max on 14.3 Vodafone UK Single Physical SIM. 4G (no 5G). Same drain as 14.2.1 and 14.2 and 14.1 basically. All that time I didn’t use it at all except to check the battery life on 2 occasions for no more than 10 seconds a time. 11 Pro Max on the same network is still on 69% and it’s been very nearly 2 days since I last charged it and it has over 3 hours screen on time already. On average I get around an hour of usage per 10% battery on my 11 pro Max (unless I’m gaming) and overnight drain is always less than 5% (usually around 3%). On the 12 Pro Max I’m lucky to get half an hour out of 10% battery and overnight drain is around 15%.

From Toronto, Canada

1st Night:

When I upgraded to 14.2, I noticed a huge battery drain overnight on standby anywhere from 10%-20% on iPhone 12 Mini.

Upgraded to 14.3, and after one night it dropped only 5% in 7 hours of idleness (without wifi, only LTE).

Will see tonight whether it is the same case.

2nd Night:

After the 1st night, I thought the problem was gone, but it reared its ugly head again! This time to my dismayed it dropped 21% in 8 hours of idleness (same settings)!

Will see tonight whether it is the same case.

This is my fear...waited since the iPhone 6 to upgrade and now most likely Apple blew it with a power hungry modem all for the buzz word of 5G which is more or less non-existent and unnecessary even if it is...🙄