Everything in an airplane is a compromise. I have friends who wrestle with their Russion air start system. They carry a scuba bottle to recharge it after it leaks down when they are parked for a while. I will guess that the scuba bottle is not figured into the official empty weight of the airplane but they never leave home without it. Electricity is much better if you are flying somewhere south of Siberia....

Best of luck,

Wes
N78PS