This is one of those things that just won't die. There is nothing wrong with the Lumia 920 battery life. Nothing.
-joe-
I would argue you are correct on a technicality. I do believe there is nothing wrong with the Lumia 920 with regards to battery life. However, I think there's been more than enough evidence that there is something wrong with battery life concerning either Windows Phone 8 or with one or more of the apps it uses.
Case in point. Right now, my battery condition (from the Settings menu, I don't use any battery apps) is 71% at 10 hours since last charge. Now, to provide a level of detail as to what went into that:
~3 bars of LTE for cell connection
Wifi off
NFC off
Bluetooth on
Touch sensitivity High
1 email account push (Gmail)
2 email accounts checked every 2 hours (Yahoo, iCloud)
Only 1 app allowed in background, WeatherFlow (update in 1 hour increments)
No additonal items pinned as live tiles, only what comes with the OS (WeatherFlow is used on lockscreen, not home)
Usage:
Sent three text messages
Added a password lock to the lockscreen
Checked battery usage in settings four times
1 internet search
Always, always, always use the back arrow key and close out apps when I'm done with them.
Now, 30% in 10 hours with that level of activity isn't terrible. Not outstanding, but not terrible. But, the kicker of the story is this: the drop looked more like: from 6am-11am down from 100% to 78%, and from 11am to 4pm down from 78% to 71%. That's a pretty radical delta in drop between the two times, especially with such light usage...from roughly 4.5% per hour (yes I know...not completely accurate, but as an average) to roughly 1.5% per hour. As a breakdown, two text messages, the quick internet search (looked up a definition of a word) and two batter checks in the first 5 hours, the rest in the second 5. The big difference....at 11 when I noticed the draw I performed a power down (held the power button down, slid down to turn off, held the power button to turn on). Nothing was changed in settings, and each time I made sure after doing anything to spam the back button to make sure that nothing was remaining running. It's not the first time this has happened to me, and definitely not the first time it has happened to many others.
It's pretty clear that there is some sort of rogue process that is eating up battery power and isn't showing up on the app list. I tend to like the idea of the GPS as the culprit as I've occasionally seen the icon in the top bar appear even without any apps using it having loaded. As well most of the time (I believe every but I can't be 100% sure) the upper right portion of the phone when looking at the screen feels very hot at the times the batter seems to be draining rather precipitously. I can recall a few times when the phone hit battery saver mode (20% left), even with that on and doing nothing with the phone within two hours it would drop to as low as 7%. And yet other times I can spend over an hour on the phone, maybe 100 or so texts, a few hours of listening to music, and maybe an hour and a half to two hours of web surfing and still not even hit batter saver when I finish up for the day.
Something is definitely going on, and I think it is incumbent upon Microsoft AND the handset manufacturers to try and come up with a fix. Having been through similar issues with a number of iPhones, and a few other smartphones, it doesn't surprise me that something like this is happening when moving to a new hardware platform coupled with the first release of a new OS. Bound to be growing pains, and my past experience is they usually get sorted out. It seems perfectly within the capability of the manufacturers and developers to identify the cause of the problem and to provide some sort of fix...the question is whether or not they will.