Quick Droid turbo battery review:
The only way you will get 48 hours from this battery is if you don't use your phone for 2 days. That doesn't mean it has bad battery life. I can wake up at 6am and by the time I go to bed at 10pm the battery will be at 15% with 5 hours of screen time while streaming a couple hours of audio during my commute. On a busy day where I'm not really on my phone it can last me the entire day then I can go out and keep checking it till around 10 am-12pm the next day with 3.5+ hours of screen time.
Not 48 hours but damn good battery life. And if it is running low the turbo charger gets you good to go again pretty quickly.
It's all relative. By the way typically I use my phone (stream music) while browsing sites like GAF, screen on for an hour or so daily on commutes, chat on hangouts, occasionally stream video, etc with pushbullet, gmail, drive, calendar, chrome, music, dropbox, etc sync'd with Google Now on - my phone get "three day battery life".
If I were to start gaming, that would probably turn to 1 1/2 to 2 day battery.
The first day I got my phone was the day I hit it the hardest. From full I got 6.5 hours screen time and I believe 10-12 hours (downloading a lot of apps and using non stop). I'm sure the battery has improved since then.