GWS offer this LV system for small indoor application to save those who is using 9.6V 8cells 50mah. How much this will cost you? While todays Li-ion battery one sigle cell of 3.7V 1.2~2Ah cost you less than that, give you more ennergy and weight light.
For speed 400, you can pay for AA, SC... good capacity and cost performance OK with Ni-cd or Mi-H. Not a time to use Li-ion for Big airplane yet!
But you can see battery vendors have great improvement from time to time, a SC size pack from 1.2ah up to latest 3ah, wasn't that a great deal?