How many hours can an iPhone original last? ?

Download a battery app and it will tell I u much time u have left if you put your phone to these settings u hv just told me. I personally use this thing called animation battery that's free, works well, oh and iOS 4.3.3 increases battery time but u can't delete loading apps anymore which ticks me off??? Well good luck, there r plenty of apps out there that can help u with it and use installous to get a really good one if u dont want to waste time on the app store