18650 button-top Lithium-ion battery rechargeable up to 500 timesCapable of charging a single battery or two simultaneouslyDual input accepts either 5 V micro-USB or Streamlight "traditional" AC or 12 VDC power sources (USB power input only, does not charge USB devices)Individual bay LEDs for battery charge statusMicro-USB input with custom locking feature charges from Streamlight® AC/USB adapters or most other USB sources (charging input only, does not charge devices)Charger temperature safety circuit prevents damage to batteries while chargingTurns high performance flashlights into rechargeable systemsAdds flexibility to wherever and however you use your Streamlight® flashlightUSB rechargeable batteries for charging on-the-goBatteries can be recharged using the micro USB port in the battery (with a cord) or via the charging cradle