iPhone 12 battery draining fast

That’s either O2 or Vodafone. I really suspect that it’s somehow between the modem firmware and the carrier system. Did any of you guys contact the carrier about this? I get my Vodafone business sim replaced anyways in the next couple days for three so no point for me. I’ll try again with the new Three SIM card.

I’m on Vodafone and I notice drains of around 2% per hour (15% per night) on the 12 Pro Max. I’m getting a replacement tomorrow but I’m skeptical whether or not it’ll be the same, after reading all the pages and pages of comments here. I also notice it drains faster during normal use, for example the old 11 Pro Max can squeeze 4 hours of social media into 20% of battery. The 12 Pro Max is lucky to squeeze 2 hours of similar activity into the same 20% drain. And this is without even using 5G...I dare not think how bad it will drain on 5G. Apple better fix this, considering they advertise the same battery life on the 12 Pro Max as the 11 Pro Max.

I’m on my 4th replacement now. Got it yesterday. After downloading all my apps and setting up my new 12 Pro Max, I had 58% battery remaining and decided to put it on standby at around 9pm with my Apple Watch connected. I woke up after 8.5 hours and the battery was surprisingly at 54%. My previous 12s didn’t perform like this. I won’t throw a party just yet but I’m really happy. I hope I finally got a unit that doesn’t have the battery drain issue. Fingers crossed. Will update after dew days.

You can request a eSim on Telekom's website. I did, and I was on eSim in about 15 minutes. It goes really fast. And... it made no difference. Signal strength is the same (approximately -112dB), Battery drain too.

that's pretty strange. I got a colleague with a new iPhone 12 pro as well. she checked her battery life for me and her device loses like 2-3 % battery over night (sill connected to her Apple Watch) she has a German Congstar SIM card...

I had 4 different android smartphones before this iPhone and they all got me to 2-3 days. iPhone 12 pro due to corona and a lot of work with less usage lasts only one day.

I really hope 14.3 will make a difference

Switching networks just to fix this problem is a very drastic solution! Most people on here didn't have the problem with the same network in the same locations with previous models of iPhone. Apple clearly have an actual problem with the modem in the 12 which they need to fix - urgently - rather than all the customers experiencing the problem needing to change network. For many people that won't even be an option anyway - anyone locked into a contract can't change network until the end of the minimum period.

Sure this is what we mean by carrier problem. Maybe not phrased correctly as it’s clearly a problem caused by Apples new firmware for the modem. Looks like they don’t talk the same language with certain carriers. It also seems the problem is pretty much isolated in Europe.

I have a 12 mini and have noticed a 15-20% drain at night while I sleep if not charging. What is strange is I did not have this issue early on with the phone. I’m wondering if it may be a specific app. I’m going backwards removing recent apps I have installed trying to see if it makes a difference.

I totally understand the frustration. I had to have 3 replacements/exchange (not replacement units) just to get a phone that doesn’t have this issue. I guess I was lucky with the 4th one cuz it would’ve been my last exchange otherwise I’d be going for a refund.

The SIM being out of the phone will disable the cellular modem, so it isn't necessarily anything to do with the SIM itself - it's more likely to be a modem problem, which may also be more prevalent on certain networks.

m2linchen wrote:

1. When I use dual sims(China Mobile and China Unicom), if I set China Unicom as the cellular data sim, the battery drains 20%-30% over night. But if I set China Mobile as the cellular data sim, the discharge curve of the battery is back to normal.

2. When I use single sim(China Unicom), the discharge curve of the battery is still good.

The above results indicate that it is a potential bug in iOS.

Update:

I am now using China Unicom as the cellular data and China Mobile as the default line. The discharge curve is still ok.

So this is really weird since I didn't do anything.

I tried turning wi-fi off on mine (I tried literally everything...) and it made no difference at all - the only thing that did was airplane mode.

Also, be careful of making judgements based on the percentage change in a single hour - the percentage isn't particularly accurate; you need to let it run for 3 or 4 hours and look at the bar graph to see if it is still falling.

If turning off wi-fi does fix it for you, that's great, but it certainly doesn't fix the drain on all phones.

Last night I did a complete restore to factory default with no apps installed, just a fresh phone, wifi on and two SIMs. Overnight the phone lost 6 percent battery between midnight and 08:00. That seems not too bad at first sight, but my iPhone 8 (same fresh install) only lost 2 percent. While talking to the Apple senior advisor I got the feeling that engineering has no clear idea what is going on after all the information I shared with them and all the tests we did. The best suggestion he had for me was to bring the unit into a Store for 'hardware diagnoses' or send it in...

Wow, I buy a new unit every single year and I never -ever- had such major battery issues as this year, it's really taking away all the fun of a new iPhone.

"It's unclear where the problem lies; it sounds to me more like carriers have an issue they need to fix than Apple does."

No, Apple have an issue to fix. Carriers should not need to update their network to cope with a particular handset. Other manufacturers' 5G phones do not show this issue, nor do Apple's previous non-5G phones - and the issue occurs even when 5G is not used. This is a problem specific to the iPhone 12 - it is Apple who need to address it.

"I don't understand why everyone doesn't leave their phone on a charger overnight like most do; that way your phone will do its iCloud backup while you sleep as well."

As has been pointed out to you before, whether or not people charge their phone overnight is irrelevant to whether or not a handset has a fault. For a light user, having to charge every night shortens the lifespan of the battery. Irrespective of whether or not users choose to charge every night, this power drain is a problem which should not occur and which should be fixed.

My experience. Iphone 12 mini bought on December 1st, first full charge while downloading backup from itunes. Never recharged from 21 pm December 1st to now. Used very little, only settings, notifications, a 2-minute phone call, 6 minutes of gaming: it is now at 20% after about 58 hours, most of which in stand-by. Night consumption first night: 5% in 7h, one sim, wifi on, all battery saving settings applied. Second night consumption, on air mode on: 2% in 7h. Third night, on air mode off: 4% in 6h. While the old iphone 6S, with 76% battery status, in the same condition never lost anything from 100% overnight!