The iPhone features an internal rechargeable lithium-ion battery. Like an iPod, but unlike most other mobile phones at the time of its launch, the battery is 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. A distinction to Android devices is that connecting an iPhone to a charger while powered off causes it to power on rather than showing a battery indicator without booting.</q>