This is referring to the new style manual battery's I have one that seems to last 4 hrs and the other seems to only last about 2 hours from a full charge. both batterys are always used down to when the light blinks 20 times then recharged and both were put into service at the same time. also ive rotated them around as to time of day useage so it doesn't seem to be that one is seeing more vaping or charging than the other.