The whole letting it discharge is wrong. Lithium based batteries do not like this. They like partial charges. End of story. I do not want to get technical (have done it in other threads elsewhere, and no one really understands), but PM me if you want, and I can.
-Nkk
Citation: I am a Chemical Engineering/Physics major working in a materials science battery lab focusing on the resetting of Lithium ion batteries. Oddly relevant, no?
EDIT: This is not to say never let them discharge. The overall bad done if you do it once may be outweighed by allowing your phone's battery indicator to correctly calibrate.