So this may be a silly question, I may be overlooking the obvious. I know my mvp has a 2600mah battery. But, when I push the "u" and "p" together I know it's telling me the resistance of my atty and have read that the second number is the amount of battery left. And at certain voltages left will determine the led color of the fire button. To my knowledge voltage is a measure of the flow of current put out or in not capacity of a battery. I realize the voltage output would decrease as the battery is drained, but how Can it put out 5v if the battery level is at a lower voltage.