The iPhone’s large display, networking features and powerful processor all take a toll on battery life, and the length of life on a single charge depends largely on how much you access these features. Moderate use can get a single charge through more than a day, while heavy use shortens the effective life to a small fraction of a day. As with all rechargeable batteries, the lifespan of a charge will decrease as the iPhone ages. Writer Bio

The Average Battery Life of an iPhone - 90