iPhone 6 on iOS 9 drains my battery while in standby

[Ashin]

Thanks Ashin. I'm glad I asked my question because that's a whole load of interesting information that you replied with.

My phantom usage does seem to be less with iOS 9 installed. I've had my iPhone 5 off the charger for over 24 hours now. Since being off the charger I've only hit the home button maybe 3 or 4 times to take a peek at the battery percentage, didn't even swipe-to-unlock it on any of those occasions, so maybe 4 x 30 seconds plus a minute just now to actually unlock and look at the usage stats = 3 minutes total genuine (as opposed to phantom) usage.

Having just unlocked my phone to look at the battery stats in settings it is showing 51 mins usage and 28 hours 16 mins standby. That's a lot better than the 2 to 3 hours of phantom usage that I would typically have seen with iOS 8.4.1 but still disappointingly high for a phone that really should be doing nothing at all as far as usage is concerned. There's currently 78% battery remaining by the way on an iPhone 5 phone/battery that's just a few days over 2 years old. iOS 9 does seem a bit better on phone battery life than iOS 8.4.1 was; it's certainly way better on my iPad Air and has probably added at least an hour to my usage time if not more - more experiments needed there.

I suppose if I'm going to be optimistic maybe at least it's good to know that there is scope for Apple to reduce standby drain further, at least for people who like me don't want much auto-updating stuff like automatic photo/app/ibook/etc syncing enabled.

Try downloading XCode if you have a Mac, and open up Instruments to watch the process activity.

My "tweaked" iPhone on iOS8.4.1 (no buggy iCloud features going crazy) and other stuff disabled (Siri, iTunes Connect, Background Refresh, etc) only clocks up around 4-5 minutes of phantom usage over night (8 hours).

 

[Ashin]

I think the definition of 'usage' is not only when the screen is on, but also when a certain class of activities are being executed with the screen off (and honestly I would not know where to set the line there).
For example a few days ago I've noticed that the Facebook app tends to put together enormous amounts of background execution, I got maybe 40 minutes of background even with a couple of minutes of onscreen time, with background update set to off. Digging a bit deeper, I've found that background updates are something different than background execution: which is when the app has some tasks to complete after you leave it or (in Facebook's case), when it's listed as a VOIP app: this gives some more rights to wake the system and check stuff that are not related to the 'background update' setting.
Btw between yesterday and today I've got 9 hours of usage on my 5s with 15% battery left, and I've left the phone disconnected overnight.

If you have a runaway system process that adds 4-5 hours phantom usage, is that really "usage"?

That's my point...

 

[C DM]

If you have a runaway system process that adds 4-5 hours phantom usage, is that really "usage"?

That's my point...

It's usage as far the phone's resources (in particular battery) being used up. It seems that it's good to see it reflected in some way, otherwise you might see faster battery usage without seeing any information about something using it up. Now with the percentages and runtime of different apps being listed it helps with that kind of thing that much more.

The addition of a separate overall on-screen counter in addition to the other two that are there would certainly be good, but it has never been there in iOS, so it's nothing new or different.

 

[ed.]

If you have a runaway system process that adds 4-5 hours phantom usage, is that really "usage"?

well, I'm sure Apple and every developer would be *glad* to find a way of recognising, killing and restarting a runaway system process. The fact that they don't is I'm afraid due to the complexity of the system and not to some kind of ill will on their part. Now, if your point is that apple can't code for **** I would agree with you on some points (iCloud drive compared to dropbox sync speed and responsiveness anyone?), but honestly runaway processes only seem to appear as crufty leftovers after long usage and it doesn't look to me that they are part of the out-of-the box iOS package.