By Tobias Carroll When thinking about the future of commercial flight, enthusiasm for the possibility of electric planes runs into an unfortunate quality of the batteries required to power them: they tend to be very heavy. This isn’t as much of a problem for cars and trucks, but when you need to get something off the ground and keep it there for a prolonged period of time, those questions of endurance become much more of an issue. All of which might make the work being done by a Vermont-based company, Beta Technologies, that much more vital. A new article in The New York Times details the proc…