Any apps that run in the background will eat battery. But the biggest hog is the display on an Android device. If you don't have the display on a lot, you're going to find that the battery is pretty long lasting. I also use my Merlins with it at work, which means volume is usually at 50% or below. I got home today with 42% left, device unplugged for 11.5 hours, and probably a good 5 of that had music playing. You aren't going to have to hunt for ways to maximize battery life, it's pretty good.