Lithium-polymer batteries are much better than the old Nickel-Cadmium batteries we had when I was a kid. Also, brushless motors (with electronic controllers) a

Lithium-polymer batteries are much better than the old Nickel-Cadmium batteries we had when I was a kid. Also, brushless motors (with electronic controllers) are much more efficient than brushed motors. The power to weight ratio of electric propulsion in the last 10 years is incredible.