iPhone 12 battery draining fast

I was having this same issue with rapid discharge of my iPhone 12 Pro. It seemed to become much worse recently, requiring me to recharge my phone two or more times during a normal day. I have found a workaround which seems to help, although I admit I have no idea why it works. I downloaded and installed the iOS 14 Beta Software Profile and the rapid battery discharge seems to be abated.

After installing the iOS 14.4 beta on my iPhone 12 Pro I left the device idle all night (background app refresh turned off, Bluetooth and wifi on) after charging it up to 100% and unplugging at 23:30. By 8:30 am the battery has dropped down to 84% which is a significant improvement to iOS 14.3 but doesn't completely solve the problem.

Here's a screengrab:

Another weird thing happening

I had this steady drain again. Not quite as drastic but still suspicious. Normally in airplane mode the iPhone would drain around 5 percent but it was around 15ish today again. The point marked by the arrow indicates what I did at that exact time. Which was setting Mail accounts to ‘manual’. Not just on the bottom at the fetch schedule but also for each and every individual account.

So 14..4 with modem software 1.42.03 is now released, so we can talk about it: no, it does not solve the drain, still 20% on idle in 8 hours over night.

It is the hardware, seems more evident. Apple seems to be ignoring this and us users. Very sad.

If you want, you can try replacing your SIM card. EE will send you a new sim which will be 5G compatible. If you are on pay as you go, 5G won’t work but the option will still be there.

Or just order a new pay as you go sim, test it, and then transfer your current number later.

Just as an addition to my last comment: I tested the Pixel 4a, which has 50% (!) higher battery capacity than the iPhone 12 Mini. Result: Youtube Video App drained the exact same percentage, as did browsing (1% drop every 5-6 minutes). Only calls via the carrier drained the Pixel battery about 1/3 less compared to the iPhone. Also, standby overnight (7 hrs) only drains 2-3% of the Pixel, while it is 6% for the iPhone.

So overall, compared to Pixel, the iPhone is pretty efficient but needs improvement regarding talk times. In average, I get 6.5-7 hours screen on time at home (mostly wifi) with ios 14.4 and still have 20% battery life left (Apple watch paired at all times, Airpods paired about 2 hours per day).

Yes, currently waiting for a call from senior adviser. Not sure if it’s worth trying device replacement, unless it’s a new device and not one of those serviced ones. And then people reported that replacements still had the same issue. So I believe it’s a software issue which depends on mobile network configuration in the area.

Although I should say that it drains a bit less on 14.4, like 15% overnight instead of 20-25% on 14.3.

Note that high 5G power usage is normal right now for all vendors of 5G devices.

CNET reported:

CNET's global testers noticed that using 5G on phones like the Moto Z3, Galaxy S10 5G, and LG V50 seemed to tap their battery reserves faster than 4G networks. 

After at least four hours apiece of relentless 5G testing, the batteries on our test phones drained significantly. In the case of the Moto Z3, four hours of testing completely zapped the Mod attachment, which cut off 5G capability. 

https://www.cnet.com/news/the-6-hardest-truths-weve-learned-about-5g/

Likewise, Samsung states (emboldening other than the headline mine):

Samsung phone battery drains quickly on 5G service

You may notice that your phone's battery drains faster than usual while you are connected to a 5G network. This is a limitation of the current 5G networks, and will be improved as the networks expand.

At this time, the 5G networks are only used for data connections, and are not yet capable of carrying phone calls and messages. Your phone will need to maintain a connection to the 3G or LTE network in addition to the 5G network so that phone calls, text messages, and data will be delivered consistently.

Because your phone is connected to multiple networks simultaneously, the battery will drain faster than one would typically expect, and the phone may get warmer than when solely on 3G or LTE.

As the 5G networks grow in capacity and capability, they will be able to handle more of your phone's functions with less battery drain.

https://www.samsung.com/us/support/troubleshooting/TSG01201462/

The above is a limitation of the cellular networks, not of the device, so is also true for iPhone 12 family devices connected to 5G services.

Just like you I used to be on giffgaff, with no solution to this problem, I switched to virgin mobile long ago, I wasn’t ready to wait for updates to solve the issue. And with virgin, touch wood, all has been fine. But I must mention that were like 2 separate random days in between when I faced battery drain on virgin. But otherwise it’s ok. I still hope that iOS 14.5 will bring some improvement in stability and battery life overall to the iPhone 12.

P.S. Virgin offers 5G too.

Still quite a drop overnight but you left 4g on.

my 12pro max, with just wifi left on drops about 3% overnight. I get 3.5 days from a charge ( 100% down to about 4%) but am not a heavy user.

mine was losing 35% overnight before IOS 14.4

The simple answer is iPhone 12 lineup has flawed modem which drains battery depending on mobile network local configuration.

In my experience, signal strength doesn’t matter, neither background app activity (at least not much). It can drain battery on full signal like crazy and then almost no battery drain with one bar signal.

The only way to prevent battery drain is airplane mode or switch back to iPhone 11.

I just gave up. I’m waiting for the 13th model so that I can get rid of this 12 pro crap.

I deleted a couple of apps thinking they were the problem - including eBay. The problem resurfaced after a few days, but I hope it works for Helen.

I postponed my trip to the Apple store, as I seem (famous last words) to have got rid of the problem by switching to "low data mode". Every couple of times I charge the phone I switch it back to standard setting when plugged in.

I did think it was just luck, but then I left it on standard whilst unplugged, and the issue returned. I am not promoting this in any way as a solution, but it worked for me.

Ridiculous really.

Krish,

i gave figures with Wifi, Bluetooth and Mobile Data all off, since i normally turn these off overnight.

however i left all three on last night and over 10 hours and the battery level dropped by 5%, compared to typically 3% with all off.

i am not a heavy phone user and since i am at home much of the time at present it is mainly on WIFI , but my 12 pro max usually lasts 3-4 days between charges. I font charge until under 3% and always charge to 100%

updated to IOS 14.5 battery still good

Hi Dimeso, my only suggestion to manage this issue at the moment is to charge your phone to 100% before sleeping. That will lead to no drain overnight. Please do keep in my mind that this isn’t a fix but just a way to encounter the problem. Hope it works for you. Good day.

It seems that out of the large number of iphone 12 sold a small number of us have experienced significant battery drain issues.

mine dropped 20-25% overnight doing nothing. Look at your battery drain ( settings battery) if level is pretty flat when phone not being used, you dont have a problem. It sounds like yours is fine. Apple refuse to acknowledge this problem yet they gave fixed it ( for some at least) in IOS version updates. I am nit a heavy user, my phone is mainly on wifi used several hours a day for internet email etc, battery lasts 3-4 days between charges.