iOS 11.4 and iPhone 6s Battery is Horrible

You might be on to something. I was away from wifi for half the day - in that time, only used 5% of the battery (with several phone calls). As soon as I got back to my office (using 5 GHz WiFi), the battery started to drain like crazy - I believe there is something connected to wifi and battery drain.

Disabling location services seemed to work for a bit. But I charged up my phone last night before going to bed. It was 100% when I went to bed, when I woke up this morning it was down to 15% battery left. So I did a factory reset this morning, then restored it from back up and charged it up again. So far the battery is back to performing as normal. I hope 11.4.1 is released soon with a fix for this issue.

Mike, I tested your theory regarding 5Ghz, versus 2.4Ghz. I think you are on to something. For perspective, I disabled all location services, and had my battery replaced 3 days ago, and the battery drain was still horrible (after the 11.4 update). While off WiFi much of the day (cellular only), the battery drain was next to nothing - with several calls. When I got back to the office, the 5Ghz WiFi locked in, and I could watch the battery % drop before my eyes (and the phone gets warm doing nothing). Then, I switched over to 2.4Ghz WiFi, and the phone was using battery about the way it did before the 11.4 update (and the phone cooled down)! I do believe something in the 11.4 update has affected how the phone reacts with WiFi, specifically 5Ghz WiFi.

Same here.

With 11.4 I'm experiencing fast battery drain when wifi is up, *and* when i'm more than 10 meters away from my router.

When I'm close to the router, battery remain stable.

When using safari in my bedroom, 15m away from the router, battery usage is about 20% per 30 minutes.

I haven't noticed any differences between 2.4 and 5ghz, but most of the time I'm connected to a 2.4ghz ssid (for better range than 5ghz).

Also, before sleeping, I always set the phone to plane mode, and when I wake up, battery consumption is minimal (0 to 1%).

At work, I have no wifi connection, and battery usage is normal.

For me Wifi management is definitely the culprit.

I have also experience this situation. If I leave the iPhone at 80% at night, in the morning, it is completely dead. I restored the phone on iTunes but the problem persits. Apple support was unable to find a solution.

And it is not the battery, I had the battery replaced by apply less than 3 months ago. Hence, it is all software related and Apple need to fix it.

This in not a problem that a new battery will fix, don't wast your time. Exactly the same issue on 2 iPhone SE's that had their battery life cut in half. I was lucky and just managed to get both downgraded to 11.3.1 before Apple stopped signing it yesterday.

Immediately, battery life was back to normal.

Apple should strongly consider signing 11.3.1 again until the root cause is identified and fixed.

Says reply but wanted to leave a response for myself, so yes after 11.4 update my battery power on my 6S is horrid, just overnight it will drop from 100% to 40-50. I never had the problem before and with all the texts and reply’s I doubt it’s just a battery issue?!?!

Brian, this is the 4th time you sent the same message (just in this forum) - are you being paid to post this message to replace the battery? As all of us keep saying, it is not the battery. Like a fool, I did replace my battery - that was not the problem. The problem is with the 11.4 update.

@Briansyddall - stop telling people it's their battery that is at fault, it's a bug in 11.4 plain and simple. If you'd bother to read all the people that are having this same issue even with new batteries, heck even some iphone X user's are having problems. It's caused by the wi-fi connections, the 5G band that is the issue. Running on 2.4G (or non-5G connections) worked for me. I also just did a Network reset in the iPhone settings and added my passwords back for my home 2G and 5G bands on the home router. I can now say that battery drain is normal on both bands. This is the simple trick that fixed my severe drainage on my 6s.

Yeah, it’s not likely for everyone to be a physical issue with the battery. I’ve noticed a tremendous reduction in battery life, and iOS says that I’m mostly just using a Safari (about 80%). I never got anything near Apple’s published estimates before, but I’m getting considerably less time than even a month ago.

Thanks for the tip on a network reset. I tried it. It appears to be better, but still not good on 5G. Before I did the reset, I could literally watch the battery % go down before my eyes. Now, the battery drains about a % every 3-4 minutes doing nothing (which is better than it was). So, I switched back to 2.4G.. Although it is better with the network reset, the drain is still about triple on 5G versus on 2.4G for me (also have a 6S phone).

I have good news on this topic: The battery drain issue with iOS 11.4 on an iPhone 6s is TEMPORARY! I had the exact same problem as everyone else on this thread after upgrading to 11.4: Battery replaced less than a month before the update, then immediate battery drain after -- 50% by noon, <25% by 10 PM, with less than two hours use (i.e., MANY hours on stand-by only), and all the usual suspects (Background refresh, Location services, etc.) turned off. This went on for the 72 hours immediately after I installed 11.4. Apple had NO suggestions on how to fix the problem (other than the "genius" at the store using it as an excuse to try to up-sell me to an iPhone 8 ("You might want to explore some different ownership options...")). With no other option, I decided to just watch it, and patience paid off! On the fourth day after the install, miraculously, my 6s went back to normal battery usage! No changes needed. For example, it's now 2 PM, and the battery is at 91%. Apparently, 11.4 needs 3-4 days to complete all of its housekeeping -- and burns a lot of battery power doing so, before it settles down to normal usage rates. So, my suggestion: tough it out. Keep the charger handy for midday recharges if needed in the first 3-4 days, and be sure to plug it in overnight for full charging every night. By day 4 or 5 you should see everything return to normal -- without having to tie your 6s in knots turning stuff off, and changing network settings. Good luck!

Russca, glad to hear you are out of the woods!

However a week after the 11.4 update I am not and my 6s still exhibits bizarre battery drain if Location Services are turned on. LS off, almost normal pre-11.4 performance.

May Apple fix this and may your good fortune appear in other phones.

This is an outrageous example of Apple's lack of care in making new releases. How could they possibly not test for battery impact before making a major release of this kind. In my own case, my battery, which lasted for three days of usage before the update, is now exhausted in less than five hours. What a mess!

Good to hear it's working for you, Russca. Sadly not for me. It's been well over a week and still, as soon as I enable wifi, I can see the battery percentage remaining indicator start ticking down with alarming rapidity. I disable wifi, and the battery life is back to normal. This continues to be the case. I'm periodically re-enabling wifi to see if it has improved at all but so far with no joy. I can only hope that 11.4.1 comes out soon.