I just leave mine on all of the time, there's an increased drain but not huge.

Sat at work today, watched a Futurama movie, 1 hr 22 minutes. Bluetooth paired to my A2DP headset, playing in CorePlayer.

The whole hour and 22 minutes only drained the battery 12%... pretty dang impressive because if I were to browse sites for an hour and a half, I'd have lost a lot more than that.