It is possible to replace the battery on an iPhone. As of 2015, Apple offers free replacement of iPhone batteries for up to a year after purchase, assuming that the phone has not been tampered with or damaged. After the warranty period, Apple replaces the battery for a service charge.
Users can replace an iPhone battery at home with a commercially available replacement kit. However, the construction of the iPhone makes it difficult to disassemble without damaging the phone. Any damage to the phone voids the warranty by Apple. A private company specializing in cell phone repairs may be a cost-effective route for owners who are hesitant to try self-repair.