The new BD 1800 Rechargeable Battery and charger is the next evolution in modular rechargeable battery pack technology. Compatible with the Sprinter275 and ReVolt350, the BD Rechargeable battery comes with a USB charger and is a 1800 mAh Lithium Ion rechargeable cell, giving you the freedom or reliable light you can use again and again while running, climbing and trekking in the mountains.