Battery Problems - Why does the settings App use so much battery?

Hi Guys,

l have an iPhone 6 (one of the first ones) with iOS10 running on it and – like so many others – am struggling with battery issues. I have been reading up on this problem for the last few months now, turning off background app refresh and location services and so on, but nothing seems to help significantly. I have the issue, where the iPhone would drop from 60% to 1%, then stay like that, turn off, and after reconnecting it to a power source would show 40% charge all within minutes. Not no mention randomly turning off at 50% and so on. So I started debugging the phone in the last few days:

I move a lot during the day, so I have to connect and disconnect the phone quite a lot. I thought that might be the problem, so I charged it up to 100% and started using it without connecting to a charger. I turned off auto brightness and put it on a fairly low value. (about 20%) At first, everything seemed normal. I checked the usage time vs. standby time and it was fairly accurate. After a few hours the phone dropped to 60%. Still, a little fast, but not too strange. I tried using the phone for a few minutes, it even survived a few games of Hearthstone, dropping to 50%. So far, so good. I thought maybe the problem was fixed, but then: After it dropped to 40% while I was reading on the phone (just a regular site, no surfing, just had it open) the phone dropped to 30% in a few seconds. After I noticed this, I went to settings (29%), battery (28%) and turned on the low power mode.

Just before my eyes it dropped 12% in mere seconds. In low power mode however, it stayed like that for a while until I was home. From then on it kept dropping (not very fast, but still a little too fast in my opinion). Before I went to sleep it dropped to 3%. I wanted to bring it down as much as possible, so I could leave it turned off for a while to drain the battery a little. However, in Standby it only went to 2% in 10h, low power mode mind you, but still. So I started using it the next day and noticed something very strange. In the battery usage overview it said:

[settings app]

2 min on screen 36%

This kind of got me thinking... why does the settings app use so much battery?? This can't be right, can it? Apart from using up 30% of the whole charge, it wasn't even running in the background. Other apps have, and they still didn't use up as much. I also couldn't find anything on the forums or elsewhere regarding the settings app battery usage.

Anyhow, after using it for a while at 1% I wanted to finally get it to turn off, so I switched off low power mode and it immediately shut down. I didn't even have the time to press the back button.

A few months ago I went to the Apple Store and had the battery checked. It was still good, they said, very good even. So now I ran out of ideas. Maybe you guys have some? 😉

Cheers,

SirThanksalot