Explain to me this. Why is it that when the Air is left unplugged, and not used, the battery dies like in a week? I've got two, they both drain the battery when not in use.

2xAA
M80/VP150/VP160/QS8
4xM3/M22OW/M2OW/VP150OW/4xM3IC/4xM3OW
EP500/800/HSU VTF3/SVS PB2k/SB2k/SB-12