[Galaxy S II General] AndreiLux:
So I've played a bit of Sherlock Holmes over the last 2 days trying to monitor the AOS bug and how exactly it affects everybody.

First of all let's start with a graph:

First of all we can divide the whole time-line in 3 parts:

T1) From beginning to the second bar of phone usage

T2) From T1 to the infliction point

T3) From T2 to the end

In T1 I had the phone as such as I always had it for several days and nothing special to report there, AOS was taking up up to 3h of CPU time during that 9h period.

Between T1 and T2, I upgraded ROM from Cognition 1.20 to 1.30, and left home (You can see where Wifi is not on) and got back several hours later. Now this is the most important part as what I've noticed over times and times again, the AOS bug doesn't come up when there is no Wifi or Internet connectivity, fine and dandy as long as I'm not home (I also had no 3G for that period), as expected. AOS gains just 1-2 max. minutes per hour in terms of CPU time. At the middle of T2 I get back home, turn on Wifi and so on.

Now what blows me away is that AOS continues to just use little CPU time for about 7 hours at which I'm home. Everything works fine, I have not changed anything to grant any difference in usage.

Now sometime in the night I use check on the battery again, as I've done over time the whole day to keep an eye on the usage, and this time, AOS goes nuts as you can see in the drop in battery level after that "infliction" point. AOS was at a little over 4 hours and something at that point, and one hour later it was basically at 5 hours. I said **** it and went to bed.

After waking up and noticing my battery level dropped about 15%, I checked up on AOS and what do you know, it's at 7-8h CPU time now.

In the morning I chatted for a bit and some light browsing, I let it plugged in for a bit and that was it. At the end of the graph AOS is at 9 hours of CPU time.

To the point:

The Android OS drain is real and kicking, and it makes no sense what so ever. There is no correlation to the usage of the phone. I found no correlation to the applications I'm using. Apparently there's not even a correlation to if you have Wifi on or not, since it worked fine for me for a while.

And its effect on battery usage is also pretty much real: As you can see I marked the average drain curves over the 3 periods and you can see clearly the similarity in usage between when the AOS bug is alive and when not, a 26° curve vs. a 16° curve. So what it means that flat-line idle usage is increased 40% by this one bug only. [And before anybody tries to reply on the degree of the curves, it's only relative to my usage in the screen-shot and irrelevant for anybody else.]

I even plotted a curve over the whole time too see what it would have been if AOS usage were to be sane. Result: At the end I'd be somewhere around 60-55% instead of the 25% I am now. Of course what I did is not accurate at all but even if I'm as much as 10% off it's still a huge difference and you can see the point.

Some remaining remarks:

People say it does not matter that if your phone is idling or not being much in use, having a high AOS % is normal since it needs to sum up to 100% and that's why it happens. Get your head out of your asses and think for a moment. Firstly, of course does AOS % go down when you're heavily using the phone, because when you're actually using the phone you're using more power than AOS would ever be capable of draining when it's in Deep Sleep. Secondly, when idle and in Deep Sleep, nothing other than Phone Idle, Cell Standby, Wifi, and Android System (Under which everything that runs in the background is packed) should be using anything. A percentage is calculated from absolute values, and when it's high, its not for nothing.

As for what I'm actually running on the phone: Nothing other than Skype and Trillian, and I've already checked that those have no effect on AOS usage at all. I have no widgets other than the clock in the lock-screen. I removed all of the Samsung apps and most of the services. I have no push email or anything related running. I disabled all syncing. If I would go even more bare than now I'd be losing usability. I've tested this with a dozen different Kernels and ROMs and it's not related to any of those. (SpeedMod Kernel makes AOS not appear anymore because I believe it disables the monitoring capability of the system to actually record the usage, battery life does not change, but I've yet to do a extended test so don't take my word on it)

Well that's all for it now. I just wanted to do this rant since I felt like throwing the phone against the wall last night when it suddenly ate up 5% battery inside of an hour. So annoying when everything else in the phone is perfect.