Why is my iPhone battery draining fast after iOS 18.4 update?

Deleting the mail app was the only solution so far for me too. Mail was working in the background even when I switched on the battery saving mode. Disabling AI was also not helpful.

You rarely use your iPad, but your opening comment it says you charge it every three days.

Have you look at the battery stats to see if anything is using more battery power than you believe it should be doing ? If you’ve only just done the update you need to give it time as the device is configuring itself to this update, this will use battery power to do this. This is normal and expected but a few have faced real power draining issues and have noticed as much because the battery states have gone nuts on a what’s been shown on it.

AlmightyGTR wrote:

Did that after you replied to my comment. Same battery drain slope for last 2 hours. No change whatsoever.

All I can say is I have all day battery life with iOS 18.4.1 and don't experience the same battery drain, so there is obviously something else going on there. I would recommend scheduling an appointment at the Apple Store for diagnostics or contact Apple directly here:

Contact Apple Support - Apple Support

Keep us updated what you find out.

Hello~ Then take your iPhone in and have it checked out…

Genius Bar Reservation and Apple Support Options - Apple

Find Locations

I must also add that I personally have had zero issues with iOS 18.4.1 nor any other version of iOS 18 for that matter.

~Katana-San~

Benjamin Bruns wrote:

Fixed it by deleting 4000+ E-Mails in my iCloud mailbox! Since then the Mail app is no longer draining my battery. I hope Apple is reading this. But thanks for the new iPhone 16 Pro that I got because the Genius Bar employee thought it was a hardware issue.

Hello~ Yes…I hope Apple is reading this as well but probably for a very different reason than you are… sigh. I can tell you Apple doesn’t read here in the way one might think but things can certainly be brought the their attention.

~Katana-San~

“I have discovered the same issue.”

———-

Overheating iPhone:

Overview my above reply. I’ve noticed the same this. My phone commonly overheats this time around, but I just don’t notice until I hold my iPhone on my face it. While on a call, it is the back(where I have my palm to it). The heat there, at times, but it doesn’t always overheat. Watching a YouTube or iTunes video or just posting in these forums I don’t get that. My Battery Health is at 85%, and has been so for over 6 months. So, I’d say it’s no more in relevance to phone calls, and maybe low Battery Health. I’ve reported this to Apple. Maybe do the same.

Use an Otter Box Case:

I don’t notice it a lot, and that’s probably because I am always using an Otter Box brand case. So, you light want to consider the using the same.

Usually I charge my iPad Pro M2 11" every 3 days and there's still remaining battery. But last night after the 18.4 iPadOS update, I just found that my iPad battery drains so fast. At 1 PM I just charged the device up to 50%. Five hours later it's only 10% battery power left. Wow.

I think there's a bug on the update since I'm rarely use my iPad. Please, fix it ASAP with the new update, dear Apple.

So, didn't use my phone yesterday.

Checking battery statistics, I see the following:

20% background Mail app,

17% Home Screen/Lock Screen,

7% Weather Widget.

AOD disabled, background apps disabled, location services only when app in use, and phone was locked the entire day with nothing on the screen, mail sync set to auto.

How is it possible for mail app to all of a sudden start using so much battery life in background?

How is it possible for a lock screen on unused device to suck so much battery?

Dont even get me started on how a weather widget can drain this much battery now.

All this combined used to be less 5% percent per day in the past.

Apple absolutely screwed something up in the 18.4 update. They admit it or not. This is atrocious that ~50% battery drain per day without any use.

Did you try to see what apps and/or services are draining your battery? Go to Settings, then go to iPhone Storage, and disable the apps that are draining your phone's battery.

Same! I came here to see if anyone else noticed a substantial difference within the last few weeks. My iPhone 15, with background app activity turned off and location turned off, has been sitting at 20% lately after using a few apps off and on for the first part of the day. 🙋🏼‍♀️

Same here. Ever since 18.4 my phone’s idle battery drain is immense. I used to get less than 1 percent per hour. Now it is 5 percent per hour. AOD disabled, background apps disabled, location services only when app in use.

this is not normal.

Last week for my iphone12 pro max got 18.4.1 upgrade and when it populated from that time my device started getting hot and draining battery continuously. Over wifi i have downloaded and installed 18.4.1 on my device. After wifi it was setting up upgrade related things and after upgrade as well device was getting hot continuously.

In night i kept it 90% charged and in morning when checked it was switched off. Once came up, from that time to till now device is getting hot in ideal scenario. Without using device, it's battery is getting drained and not helping to keep device usable.

2-3 times i need to charge it and while charging as well it's getting too much hot and giving high temperature warning on screen.

Please suggest fix for device hot and fast battery drain issue. My device was working without any issue before 18.4.1

I tried all possible ways to stop background activities for apps and other things. But still no luck and battery is draining fast.

My battery health went down from 100% to 95% within 17 months, but just during the last month it went down from 95% to 91%. Its alarming and I dont know what to do to stop the battery to go bad this fast. Im still using the same charger, using charging cap to 80%, using the phone still the same. Its suspicious it happened the same month the 18.4 update was released.

I have 15 Pro Max with 305 cycles.

I see, got it, but would be strange for it to happen like this only during last month. I will try to let it charge fully and see I guess then. Thank you for the tip.

So here’s something even more interesting than my previous post. 

Ran phone in battery saver, to just get by till this bug is fixed. Guess what, slope of battery drain during idle does not change even in battery saver mode. 

So battery saver mode is completely pointless now. 

Matter of fact, my idle drain prior to this bug was 10% in entire day in normal mode. Now I am at ~50% with power saving mode.