I9505 Android 4.4 GE battery issue explanation
Reading the thread of Jamal's Google Play Edition 4.4 ROM, i noticed some users were saying they could get 4 hours of screen on time. Sadly enough this wasn't the case for me, and I think many other users can confirm. On a full charge, i can barely get 2hours of screen on time out of it, which is of course unacceptable. I decided to analyse the battery usage.
What I've got after a full discharge is illustrated in the attachment. If you know how I used my phone during this period, the curve is very surprising and hard to explain. The first hours I had my 4G on for extended periods and I noticed pretty decent battery life, i.e. 25% gone after 1 hour of screen on time. That's surely an acceptable score and would give me also that beautiful 4 hours. But suddenly, the phone made a weird change. You can see that the phone starts discharging much faster with a new and constant slope. I tried stopping it but it didn't change at all. My 4G and wifi were all set to off, even my location settings were turned off. Nothing changed.
I started searching the web if some applications were not optimised for android 4.4 yet, but didn't find anything significant. But then I found topics about the Exchange issue which already gave many android 4.4 users headaches. I read about a constant error-looping that could cause fast battery drain and, sneaky enough, doesn't start immediately when the phone boots but can start after a period of several hours. I decided to shut the whole thing off and deleted my Exchange account. Rebooted the phone and the issue was gone.
Hopefully a fix will be brought out soon!