The 3.7V, 3400mAh 18650 Li-Ion Battery with Micro-USB Charging Port from Kraken Sports is rechargeable through the Micro-USB port, and it is compatible with the NR-650, NR-700, NR-900, NR-1200, and Hydra 1000 dive lights.
Compatibility
Dive Lights: NR-650, NR-700, NR-900, NR-1200, and Hydra 1000