I looked for a forum specifically for stupid questions but couldn't find one so I'm asking it here. I got my new iP4 today and am attemping to initiate it by the book. They insist to leave the phone off and fully charge it before activating. Well, with the phone off, there are no visual indicators to tell you when the phone is fully charged. I read the owners manual charging section (with a microscope) and they don't tell you how long to charge it. How long should I charge my new iP4 to assume it has a full charge?