I wanted to give some who don't think battery life is "amazing" on 822 a quick tip that hasn't been mentioned as much as other tips. I was getting good battery life, made it through a day with moderate use just fine, was getting close to or a bit over a day with Global off, Data always on, Wifi on (whenever I'm in range of one, which is 75% of the time), NFC off, and Location off most of the time. It improved from that sort of 15-20 hour time frame into a full day and a few hours but I wasn't getting close to 2 days as others were getting. Then I saw mention somewhere else of turning off the Connect to Xbox when it wasn't needed. That's what turned my battery life around from really good to amazing. The first day with that off, I got close to a day and a half, since then, a little less than a week now, I've been getting on average, 2 days and several hours and that's streaming music for several hours, opening apps liberally, looking online, playing a few games throughout the day (Words With Friends, Wordament), and reading. I'm not restricting my use at all and still getting 2 days now.
So, in case you aren't getting excellent battery life but want it, consider going into the settings menu, swiping right and below the background tasks settings is the game settings, going into that will allow you to turn off the Connect With Xbox setting. It's clearly the thing that changed my phone around, hopefully it can do the same for someone else.