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iPhone 6(S)/Plus All of a sudden, battery life is terrible - iOS 11.4?

Darmok N Jalad

Darmok N Jalad

macrumors 603
Original poster
Sep 26, 2017
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Very strange problem with my 6S. Battery health comes up very good on coconut battery, with about 100 cycles on it, still at full charge capacity. Battery life was great until Sunday, when I picked it up around mid-day to see it was at 20%. Normally on Sunday my phone sits on a ledge and goes unused, so it would normally be at over 80% at this time (I charge to 100% each evening). Figuring it’s a rogue process, I reboot the phone. Doesn’t seem to help, as phone was still dropping 10% in less than an hour, even while doing nothing. Do the soft reset, still not much help. It’s very random, where the battery drops quickly for a while, then stabilizes, then drops.

I’ve done nothing new with the phone, no new apps, no background policy changes, just the usual auto-updates. The battery tab in settings doesn’t show anything really out of line. It only supports the notion of terrible battery life by saying I’ve used it for less than 2 hours and the battery is over half dead. :confused:

My best guess is that I also recently updated it to 11.4, but I can’t remember when exactly. It doesn’t appear to be throttling. I’d really rather not start from scratch with a hard reset.

Anyone else notice a problem or have any ideas?

EDIT--Updated title of thread.
 
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Has it ever had a replacement battery? The 6s was notorious for battery issues.

If you’re within driving range of an Apple store you may want to bring it in for a battery test. Being a 6s, you may even qualify for a free replacement (I did).
 
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My 6S was amazing, would be on 80% at the end of the day after decent usage. Then about four weeks ago it just suddenly began draining at a very fast rate. Checking an email would use 5%. I would barely get to midday before needing a charge. I even tested it overnight with a fresh factory install with just wifi enabled and no extra apps. 6.30am it was down to 19%.

When I posted about this last month I had this reply:

"A battery drain problem like this is often due to a problem with the "Tristar" power management IC. That chip gets damaged if you charge the phone using a poor quality USB charger, such as cigarette lighters."

Sounds like yours has the same fault. I looked at a video on YouTube on how to replace them. Its on the motherboard so I didn't bother. Gonna try and hold out until September and see what new models come out.
 
A quick update for what I tried next. Last night I ran the battery down until the phone shut down. I streamed video at max brightness, which it managed to do for about 45 minutes, even though battery was below 40% when I started. I then charged the phone all the way back to 100% before I went to bed, then unplugged it. This morning (8hrs later), the battery was at 99%. Now I’ll see what happens next.

Candlelight said:
"A battery drain problem like this is often due to a problem with the "Tristar" power management IC. That chip gets damaged if you charge the phone using a poor quality USB charger, such as cigarette lighters."
Click to expand...

Interesting. I rarely use a non-Apple charger, even in the car. My car has the 110V wall plug, so I just use an Apple AC adapter. I hate those cigarette lighter chargers—most of them seem very poorly made and very finicky.
 
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Seems the battery run down experiment fixed it, at least so far. Haven’t charged it since last night and I’m at 71%, under light use, which is more in line with what I normally see. I wonder what happened?
 
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Yeah sometimes these kinds of issues are really weird. I have an old 5c as a backup phone. It was dropping 1% in standby every 5 minutes. When it dropped 5%, I switched airplane mode on. Drain stopped. I tried today again without airplane mode. No drain whatsoever.
 
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Well, I may be hasty with my resolved comment. Just charged it to 100%, and an hour later it dropped off significantly again! Checked battery stats and it shows most of my battery time has been from low phone signal. It’s on WiFi calling mode at home.

I’m really starting to wonder if it has something to do with the [11.4] update. I’m running a non-Apple battery in mine, as I replaced it myself a few months before Apple moved to the $29 replacement deal. I’ve never had any problems until recently, and the battery health beta section on the phone doesn’t show any results. Coconut battery has no problem providing battery health info though, and it says battery health is still at almost 100% capacity.
 
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It looks like this rapid battery draining is related to the 11.4 (not 10.4) update. We had it here in Germany in several major news portals and I wonder why MacRumors had no news article about that. There is a big thread on the Apple Support Portal about that with nearly 1500 replies complaining about the same thing > https://discussions.apple.com/thread/8409995

It seems that Apple had a major problem with this and nobody should update to IOS 11.4 at the moment....This is definitely not resolved!
 
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AlexJoda said:
It looks like this rapid battery draining is related to the 11.4 (not 10.4) update. We had it here in Germany in several major news portals and I wonder why MacRumors had no news article about that. There is a big thread on the Apple Support Portal about that with nearly 1500 replies complaining about the same thing > https://discussions.apple.com/thread/8409995

It seems that Apple had a major problem with this and nobody should update to IOS 11.4 at the moment....This is definitely not resolved!
Click to expand...
Thanks for that info. I guess I can at least stop worrying about my phone being physically failing or go about uninstalling any of the apps. I’ll edit my post to reflect the proper iOS version. I’m a little behind the times!
 
Darmok N Jalad said:
Well, I may be hasty with my resolved comment. Just charged it to 100%, and an hour later it dropped off significantly again! Checked battery stats and it shows most of my battery time has been from low phone signal. It’s on WiFi calling mode at home.

I’m really starting to wonder if it has something to do with the [11.4] update. I’m running a non-Apple battery in mine, as I replaced it myself a few months before Apple moved to the $29 replacement deal. I’ve never had any problems until recently, and the battery health beta section on the phone doesn’t show any results. Coconut battery has no problem providing battery health info though, and it says battery health is still at almost 100% capacity.
Click to expand...

When your battery is draining, does it say WiFi ___ in the status bar? Low signal can deplete a battery from full to zero in a matter of a few hours. I've gone from 100% to 10% in 4 hours with my 8 Plus because I forgot to turn on WiFi at school and I am underground with no service.
 
Darmok N Jalad said:
Seems the battery run down experiment fixed it, at least so far. Haven’t charged it since last night and I’m at 71%, under light use, which is more in line with what I normally see. I wonder what happened?
Click to expand...

I tried this last night and the results are very odd. I let it run on battery from about 50% down to OFF by streaming netflix at max brightness. The thing ran for over 6 hours! I was not expecting this. Then I charged it up to 100%, unplugged, and went to bed. Woke up about 8 hours later and it's at 40%. It seems it is draining faster just sitting there doing nothing than it does when streaming netflix at max brightness. I'm at my wits end with this thing.
 
Mlrollin91 said:
When your battery is draining, does it say WiFi ___ in the status bar? Low signal can deplete a battery from full to zero in a matter of a few hours. I've gone from 100% to 10% in 4 hours with my 8 Plus because I forgot to turn on WiFi at school and I am underground with no service.
Click to expand...

I don’t think it’s actually the real issue, as the battery stats are measuring actual use and relating it to the whole of all use. In this case, low cell signal looked high because I had barely used the phone, so really no other apps could take a big piece of the pie. A 10% reported drop in 30 minutes with no active use will make for a strange report. Low cell is probably less than 1% when things are working correctly.

noobinator said:
I tried this last night and the results are very odd. I let it run on battery from about 50% down to OFF by streaming netflix at max brightness. The thing ran for over 6 hours! I was not expecting this. Then I charged it up to 100%, unplugged, and went to bed. Woke up about 8 hours later and it's at 40%. It seems it is draining faster just sitting there doing nothing than it does when streaming netflix at max brightness. I'm at my wits end with this thing.
Click to expand...

It would seem that whatever the glitch is in iOS 11.4, it must have to do with battery reporting. It seems like I’m still able to get the same amount of use out of the phone, but the way the battery is reporting is very different and looks alarming. The fact that you were still able to get that much out of your phone suggests it’s a OS bug that must be fixed. I’ve seen this sort of behavior before, and often times the “run down and recharge to 100%” recalibrates the battery reporting. It doesn’t appear to be working in this case.
 
I was running iOS 9.3.5 when mine started to die. I don't think it's software related. I think you have a bad tristar chip.
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noobinator said:
I tried this last night and the results are very odd. I let it run on battery from about 50% down to OFF by streaming netflix at max brightness. The thing ran for over 6 hours! I was not expecting this. Then I charged it up to 100%, unplugged, and went to bed. Woke up about 8 hours later and it's at 40%. It seems it is draining faster just sitting there doing nothing than it does when streaming netflix at max brightness. I'm at my wits end with this thing.
Click to expand...
I tried this last night. Watched a burning fire on youtube for two hours with the torch on. Then charged it up to 100% and left it overnight. Woke up this morning to find it on 33%.
 
I'm going to put iOS 11.3 back on the 6s tonight and see if that fixes the issue for now.

Edit: nevermind, apple stopped signing 11.3 so my plan has failed.
 
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Yeah, in the last week or so, the battery started draining way faster than usual on my iPhone 7. iOS 11.4
 
I debated starting a thread on this, since I figured there wouldn’t be too many tips on a fix. I’m glad I did since it sounds like others are experiencing the same problem.

I can say that the battery rundown trick has seemed to help quite a bit, almost like it’s a battery level reporting issue.
 
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Septembersrain said:
We're all with you here. 11.4 is making my 7 Plus battery absolutely terrible.
Click to expand...

So did those problems your previously report elsewhere were here on MR come back? I finally took the plunge on 11.4 and updated both the wifes and my own 7plus over a week ago and neither of us have had any obvious issues since. How does it manifest the drain to you?
 
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