Honestly, the battery life will be the least of your worries with this phone. I've done nothing to conserve battery and I routinely get 16-17 hours before I go to bed and still have 30-40% left when I put it on the charger at night. Right now for instance... off charger for 13 hours and I'm at 62% with moderate usage today.
eVERsince I got this phone I dont even charge it from the time I unplug it fully charged around 7am till I go to sleep around 1am but usually still have about 30 to 20 percent juice left! AMAZING!! and all of my post on here are from the time I got this phone. lol yup just started posting few days ago. GN2 made me do it!!