There are many apps that I use which help out a lot like Setcpu which allows you to underclock your phone you might think why would i do that? You can set up a profile to underclock your phone when your screen is off or when your battery is below a certain level and many more. Juicedefender turns off wifi, data etc when your not using it so both things aren't running at once. Greenify makes apps hibernate so they don't take up to much memory RAM, and Clean Master even though its a app to free up space, it additionally notifies you when there's too many apps running sucking up thay battery life. All of these apps combined will significantly increase your battery life.
This phone has a 1650 mAh battery, which is not enough considering that it has some pretty decent specs dual core 1.5 Ghz cpu just like MetroPCS's SGS3 and LTE capabilities. I highly encourage you to view the extended battery post and email the company in the post so they can fabricate a better battery for this phone.