The Streamlight® 18650 button top Lithium-ion battery turns high performance lights into rechargeable systems. It has a built in micro USB port for charging on-the-go. Portable power and convenient charging so you always have a beam when you need it. Use the 18650 USB battery to power your Streamlight® flashlights. Charges in 5 hours and has a safety circuit which protects the battery from overcharging. Features charge status indicator on the battery.