The XXX™ 18650 battery was created with one specific aim - to provide a safe, reliable and powerful battery. We only use Grade A Lithium-ion battery cells. What does this mean? Once a batch of batteries are manufactured, they are divided into 3 classifications – Grade A, Grade B and Grade C. Grade A cells have the longest runtime and cycle life, which of course is precisely what you want! The bottom line is that we source only the highest quality batteries to ensure you get the best possible performance from your mod.