That's good hearI deleted all my documents and it still had the same battery drain. I deleted all the music (none of my own music, it was only a couple app notification sounds and the one music file that it comes with), and then I got better battery usage. I am now getting 1% for every 8 mins, which is a big improvement over only 1% every 4 mins!
My test was done over the course of 30 mins to get a good average battery drain with the screen on.