Battery iPhone

Apple runs tests on preproduction units to determine battery life. Apple's website says that the battery life "is designed to retain up to 80 percent of its original capacity after 400 full charge and discharge cycles",[68] which is comparable to iPod batteries.

 The battery life of early models of the iPhone has been criticized by several technology journalists as insufficient and less than Apple's claims.[69][70][71][72] This is also reflected by a J. D. Power and Associates customer satisfaction survey, which gave the "battery aspects" of the iPhone 3G its lowest rating of 2 out of 5 stars.[73][74]

 If the battery malfunctions or dies prematurely, the phone can be returned to Apple and replaced for free while still under warranty.[75] The warranty lasts one year from purchase and can be extended to two years with AppleCare. The battery replacement service and its pricing was not made known to buyers until the day the product was launched,[76][77] it is similar to how Apple (and third parties) replace batteries for iPods. The Foundation for Taxpayer and Consumer Rights, a consumer advocate group, has sent a complaint to Apple and AT&T over the fee that consumers have to pay to have the battery replaced.[76]

 Since July 2007, third-party battery replacement kits have been available[78] at a much lower price than Apple's own battery replacement program. These kits often include a small screwdriver and an instruction leaflet, but as with many newer iPod models the battery in the original iPhone has been soldered in. Therefore a soldering iron is required to install the new battery. The iPhone 3G uses a
  different battery fitted with a connector that is easier to replace.