Keep yourself from getting stuck in the dark with the Black Diamond 1800 Battery Plus Charger! Headlamps are a great tool to illuminate cave depths and dark trails while keeping your hands free. When the battery goes out, your ReVolt350 or Splinter 275 becomes little more than decorative headbands. The BD 1800 gives you an additional 1800mAh with its lithium-ion rechargeable cell and included USB cord, giving you precious additional time to run, climb and bike on your schedule. Trust the BD 1800 and don't get left in the dark again!