Surefire B12 Battery, Black, Proprietary Battery, Fits SureFire Models B12 Power Your XSC. Specifically engineered to fuel the SureFire XSC micro-compact Weapon Light series" the SureFire B12 is a quick-detach" rechargeable lithium-polymer battery that can be swapped fast without removing the XSC from the host pistol. The compact B12 powers the 350-lumen XSC for up to 30 minutes. Its charge status can be checked quickly by pressing the push-button fuel gauge switch located on the side of the battery and observing the green" yellow and red LED indicators.