Olight ORB-186P36 3600mAh 18650 High Capacity Protected Rechargeable Battery and Lumen Tactical Battery Case High capacity - optimizes performance of various high-intensity flashlights Long lasting - 500 charge-discharge cycles, over 5 years of consistent use Completely protected - over discharge protection, short circuit protection High quality - Employs high energy density battery cells from Panasonic Long shelf life per charge - maintains 80% of its capacity over a year per charge