The Nitecore NL1836 is a rechargeable, li-ion, size 18650 battery with a 3600mAh capacity. Built for high drain devices. 3.6V, with 3A of continuous discharge power. Charge via compatible Nitecore chargers, which include UMS2, UMS4, Ci2 and Ci4. Internal protections against overcharge, overdischarge, short-circuit, and over-temperature.