Fenix's newest battery is an 18650 rechargeable that has a lithium-ion (li-ion) chemistry. It is capable of performing up to 500 charge-recharge cycles, and contains numerous layers of protection from potential problems like explosions, inflation, or short circuiting, because of the overcharge protection; over-discharge protection; short circuit protection. Possesses overheating protection as well, through pressure relief valve protection; microporous protection; and PTC cathodal block protection. Battery has excellent impact resistance because of steel part bolted into cell's anode; this steel part also contributes to cell's short circuit protection. Has voltage level of 3.6V, and a capacity of 3500mAh. The charge current level is 1A, with a maximum level of 2A. This item's warranty is Fenix's 12 month free warranty. The manufacturer advises that this battery be utilized in conjunction with other products like flashlights, bike lights, camping lanterns, and headlamps. They also note that the ARB-L18-3500 cell is compatible with the following chargers: the Fenix ARE-C1, the Fenix ARE-C2, and the Fenix ARE-X1.