power=amps*voltage=watts. A 7.4volt 5ah pack will deliver 37watt hours of power. A 22volt 1.6ah pack will deliver 37watt hours of power. You use the same size packs, they are just wired differently. When you lower the amperage resistance is less of a factor & things become more effecient. It is not an matter of wanting more power, instead it is a matter of using a setup that will last longer. However, I will agree that it is hard to argue w/ batt & motor//esc combos that will last you a year w/out replacement.