iPhone 12 battery draining fast

The best energy consumption of iPhone 12 and 12 Pro models we can hope for is around 1% in 2 hours (that is 9-10 days on standby). So yeah, 6% in 8 hours is quite close to the slowest (i.e. 4% in 8 hours).

You are wrong.

F.4 really improves everything, it behaves absolutely different in comparison with 14.3!

-2% per 8hours - 1st night

-3% per 10hrs -2nd.

I have fully charged my phone yesterday at a midday, now after 28 hours I have 59% of battery and 4 hours of SoT, and this period includes full 10hrs night with drain at 3%.

So this (f.4) significantly improves standby battery life. All of the Russian and Ukrainian users of our biggest russian community already pointed that the problem is solved.

@Horizont32

You just gave me reason:

"-2% per 8hours - 1st night

-3% per 10hrs -2nd. "

Yes,is better but is not fixed, that's my point.

My iPhone 11, with 92% battery degradation does not drop a single percentage during 8 hours in standby...same exact settings as my iPhone 12.

This is unreal situation and you could never explain that from the side of physics. This is a "visual" bug, because a modem uses enough of energy and takes some millivolts/hr to reconnect to the Base station or check the connection that has already been established before and then get a response from bs. This process is quite frequent to use some battery. So 1% is 28mAh for iphone 12 and that is just nothing to a modem.

nlnl88 wrote:

• I don't know if it's solely related to modem.

I tried many different configuration on 14.3, here are my results for a 7 to 9hr night:

Wifi on / BT on / dual SIM 4g ==> 30% lost

• Wifi on / Bt off / cellular data disabled + low power mode==> 20% lost

• Wifi off / BT off / 4g + low power mode ==> 10% lost

• Wifi off / BT off / 3g + low power mode ==> 10% lost

This is modem related.

Low power mode does not work correctly.

Be sure to try:

Wifi on / BT on / 3g ==> 0-5% lost

Wifi on / BT on / cellular data off ==> 0-1% lost

Well, I’m having the same issue on my iPhone SE 2020. My phone isn’t even 5G capable. Yet, the battery drains at a constant rate of about 4% an hour on standby. While using the phone I haven’t felt the drain is excessive. No idea why it’s draining so much on standby. Even on Airplane mode (where it should technically not lose any charge at all on standby) mine loses about 5-6 percent overnight even with low power mode turned on. That’s definitely not normal for iPhones. I’m not sure if my hardware is faulty. My phone isn’t even a month old. Any help?

Just got the iPhone 12 pro max (256gb). It had half battery out of the box and, after set up and activation, it dropped to 20%. I drove with it plugged in to the car charger with google maps (and only that one app) running. The phone is losing battery while charging (down to 16%). Did I just buy a paper weight?

nlnl88 wrote:

I can't try 3g anymore since my carrier (Orange France) has updated the carrier options to 4G or 5g only.

Very sorry.

But at the moment, only the choice of 3G solves the problem of fast battery discharge.

5G or 4G costs between 10% and 30% overnight in standby mode.

nlnl88 wrote:

But I still tried to disable cellular data (no 3/4/5g), without any improvement.

I've been testing for three weeks now.

Before turning off cellular data, you must select 3G.

Selecting 4G and turning off cellular data does not reduce battery consumption. I don't know why, but it is.

You have to wait for an update iOS from Apple.

Mobile data controls whether or not the phone will use a pure data connection over the cellular modem. It doesn't prevent the phone using voice over the cellular modem. If mobile data is disabled but the phone is still using 4G for voice and for periodic handshaking communications with the network, then the power drain (which appears to be due to the use of 4G and 5G on the Qualcomm modem) will persist.

Switching off mobile data does not turn off all cellular activity from the phone, and so does not fix the power drain. So it is disabling 4G and 5G which fixes the problem, not disabling mobile data.

Simon Long wrote:

Mobile data controls whether or not the phone will use a pure data connection over the cellular modem. It doesn't prevent the phone using voice over the cellular modem. If mobile data is disabled but the phone is still using 4G for voice and for periodic handshaking communications with the network, then the power drain (which appears to be due to the use of 4G and 5G on the Qualcomm modem) will persist.

Switching off mobile data does not turn off all cellular activity from the phone, and so does not fix the power drain. So it is disabling 4G and 5G which fixes the problem, not disabling mobile data.

Thank you! An excellent and clear answer.

Now I finally understand why I need to switch to 3G before disconnecting cellular data.

If 4G is not turned off, the phone can use 4G for voice transmission.

Went to Apple store yesterday they looked at my chat history with Apple Costumer Service, no explanation nor aknowlegment of any problem they just gave me a new unit. Went home to set it up and it wouldn't connect via Cellular data at all. Went back this morning after 30 min diagnosis they told me this unit had a defective modem/antenna and swapped it out for another replacement. This time I told them that I wanted to set it up right there. This 3rd Iphone 12 pro max would not even recognize my SIM Carrier. So I just insisted on a refund. Will wait until Apple makes a statement and fixes the issue. In the meantime Ill try a Pixel 5 and see how things go.

Good for you 👍

The sooner Apple investigate and fix this issue the better it will look for them. I’m considering insisting on a refund and going back to using my XS Max until around 2 months after the iPhone 13 is released to make sure everything runs smooth with that. It’s the Qualcomm X55 modem causing these issues and there isn’t a chance Apple or Qualcomm will be able to fix this with firmware/OS updates. The Qualcomm X55 has proven to be problematic on Android flagships.

So after almost a week since 14.3, the battery drain on my 12 Pro Max hasn't been fixed while my brother's 12 Pro Max has been having great battery performance.

Mine - 24 hours standby, 100-80%

My brother's - 24 hours standby - 100-98%

I can't believe how much it has fallen apart apple. I will not buy an iphone again... I was using samsung after iphone 7 for 2 years and i was never have a bug or something like that... I was using samsung galaxy s10e which is the budget smartphone and i was never having a problems like the problems that iphone 12 series have...

My next smartphone will be xiomi or samsung again, can't wait to sold out my iphone 12, and i bought it because of the ios and the design, but unfortunately it comes out that this phone is really suck.. Paid 700$ for product that cant be used normally.

sorry for my language, but it's not normal.