A common practice by shady sellers with 18650 lithium cells is to advertise a group of 4 of them as "2000mAh", but it's the total of each cell, not the individu

A common practice by shady sellers with 18650 lithium cells is to advertise a group of 4 of them as "2000mAh", but it's the total of each cell, not the individual cell ratings. So you're really getting four 500mAh batteries, which really sucks.