Every cell phone needs a battery to operate, whether it is a NiMH, NiCad, Lithium Ion, or Lithium Polymer. This photo shows a USB travel charger with a lithium ion battery. Lithium ion batteries are the most common form of cell phone battery.
All cell phones must have a battery and a way of charging that battery. Many cell phones come with cords for charging the phone directly from an electrical outlet or vehicle cigarette lighter.