The iPhone features a built-in rechargeable battery to is not user-replaceable, similar to offered iPods, but unlike to most existing cellular phones. If the battery in advance reaches the end of its life, the phone can be return to Apple and replace for free while still in guarantee, one year at purchase and extensive to two years with AppleCare. The cost of having Apple provide a new battery and restore it when the iPhone is out of guarantee is, in the United States, US$79 and US$6.95 for delivery.
Since July 2007 third gathering battery packs have been obtainable at a much lower price than Apple's own battery substitute program. These kits often include a small screwdriver and a teaching leaflet, but as with many newer iPod models the series in the original iPhone has been soldered in. Therefore a soldering iron is necessary to install the new battery. This is not the case with the iPhone 3G as it uses a different series fitted with a connector.
The iPhone 3G's battery is stated to be competent of only if up to seven hours of video, six hours of web browsing on Wi-Fi or five on 3G, ten hours of 2G talk time, or five on 3G, 24 hours of music, or 300 hours of reserve.