You're battery most likely isn't still "full"... the battery icon isn't that accurate. Just because the icon hasn't changed yet, doesn't mean you still have 100%. I just don't understand the point of letting it just idle all night without charging. Charging often is better for the battery life than not charging it for 2 days. Whether you use it for 1 whole minute one day or 5 hours a day... it's still good for it to charge it at night. You can't over-charge so you could leave it on the charger all day long, all night long if you wanted.