IPhone not user-replaceable. The iPhone can be charged when connected to a computer for syncing across the included USB to dock connector cable, similar to charging an iPod. Alternatively, a USB to AC adapter (or "wall charger", also included) can be connected to the cable to charge directly from an AC outlet. Some models of the iPhone support wireless charging. 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% of its original capacity after 400 full charge and discharge cycles", which is comparable to iPod batteries.
Nike+ Nike+ The Nike+iPod Sports Kit is an activity tracker device, developed by Nike, Inc., which measures and records the distance and pace of a walk or run. The Nike+iPod consists of a small transmitter device attached to or embedded in a shoe, which communicates with either the Nike+ Sportband, a receiver plugged into an iPod Nano, or directly with a 2nd Generation iPod Touch (or higher), iPhone 3GS, iPhone 4, iPhone 4S, iPhone 5, iPhone 5C, iPhone 5S, or a Nike+ Sportwatch. If using the iPod or the iPhone, iTunes software can be used to view the walk or run