About the same number of charges as an iPod. In other words lots and lots. The exact number will vary from iPhone to iPhone. Things like extreme heat will reduce the over lifspan and the amount of charge it can handle. Under normal use I would suspect that the battery will last most people two or three years. Considering that the average life span of a cell phone is 18 months or so most people should be fine and if you want to keep your phone lnger than that you can get the battery replaced. Apple charges $100 or so to replace the battery but wait a month and third parties will be offering bigger batteries for less money.