iOS 11.4 battery drain

Read this message from Apple regarding an exchange program for iPhone batteries for iPhone 6 and upwards.
Your phone should qualify.

https://support.apple.com/iphone/repair/battery-power

For instructions about what to do, visit this link.

https://getsupport.apple.com/

If you go to your local Apple store instead, be sure to make a reservation; there will be many with similar thoughts. In addition it has become known that battery stock is low and many countries are waiting supplies. Because of the enormity of this operation, people will need to be patient.

The offer is available world wide and will continue until at least December 2018.

We are many : https://discussions.apple.com/thread/8409995

TLDR :

1. Try to connect to a 2.4 Ghz WiFi network instead of a 5 Ghz one. If it doesn’t work then,

2. Try to disable WiFi in the Settings app. If it doesn’t work then,

3. Try to disable the location services

I too have a 6s and I too am experiencing rapid battery drain since installing 11.4. I believe my iPhone is losing about 10% charge per hour with little or even no usage -- all apps shut down, all remotely related options turned off. I even went through the annoyance of a restore.

But most importantly, I recently had the battery replaced by Apple at the Apple store!!! My battery is two or three months old at most. This is a SOFTWARE BUG, not a hardware issue.

IMO, Apple's software quality has degraded tremendously under Cook's short-sighted profit-focused leadership.

I was experiencing the same issues on my wife’s 6S and on an iPad Air, but not on my X. It appears to have been a network issue since I was having different behavior on different wifi networks both on and off. After the usual Restart, Hard Restart, disabling most of the location settings, what ended up solving it for me was resetting my network settings under Settings > General > Reset > Reset Network Settings.

Hello Apple Community,

I've been reading these posts since my own post here and I am seeing a trend appear that is genuinely not true.

Many posters believe the problem is related to 5.0GHz Wi-Fi. Let me tell you that it is NOT related to the 5.0GHz band. My iPhone 6 Plus is used ONLY in my home office. I do NOT have any carrier service activated on the phone. Yes, I use this iPhone purely on Wi-Fi but ONLY 2.4GHz. I have never used this iPhone on anything but 2.4GHz Wi-Fi and yet I have the very same intense battery drain that everyone else has since updating to iOS 11.4 (see my first post in this forum).

I have restored my iPhone with iTunes. I've had Apple Support remotely diagnose my phone with me. Should this be any different than seeing the Genius Bar people?

Good luck!

After the 11.4 update, I watched my battery drain from 48% to 26% in less than two minutes. Resetting my network settings under Settings > General > Reset > Reset Network Settings worked great! Thank you, alfredo1!

iPhone 6S

it's definitely the update. I just updated my iphone SE to ios 11.4 and the battery instantly started draining very rapidly. My battery health is still at 91%, so it's not a bad battery issue. Prior to the update my phone would last 2 days before needing a full recharge; after the update it wouldn't even last a day. Half would drain overnight without any usage. Try turning off your wifi, this made all the difference for me. Apple should release a fix to the bug because a lot of people are complaining of the same issue.

This is surely a bug in iOS 11.4: Has occurred with phones from 6s to X. No problem found with phone support and diagnostics. My battery was just replaced. Drain dramatically less with 2.4 GHz vs. 5, though speed of wi-fi more than 4 fold reduced. Beg Apple to find and fix bug.

I thought resetting the network settings had done the trick, but apparently not. But WiFi does appear to be related to the problem. I was off WiFi for a few days and the phone was fine but once I returned home and got back on WiFi, I'm once again losing about 10% charge per hour or more.

I usually do not apply to posts. However, I wan’t to contribute in helping. I too, recently replaced my iPhone 6s battery earlier in the year. It worked great! After the recent 11.4 update, my battery drops rapidly after getting full charge and my apps suddenly close while I am in them. I tried restarting my phone and that has not worked. After reading the posts, I will try the network reset and possibly not using network. Hopefully, at worst, maybe Apple will have another update to assist or I can try to revert to an older update. Thank you for your posts.

Totally agree. i saw my battery drop 80% over-night whilst connected to Wi-Fi.

Turned off Wi-Fi and over-night my phone was just on 4G - and it dropped by 5%. Huge difference.

So now i am just using 4G until Apple can be bothered to sort this mess out.

Let me know if my reply falls short in any way. Sometimes it will depend upon the country, especially where India is concerned.

If the issue appeared right after upgrade to iOS 11.4 then what's the point for battery replacement?

I mentioned the battery replacement to ensure it's clear the battery was almost new before 11.4 was installed and the problem is NOT because the battery is old and weak.