RE: DL-50 engine
No wrench thrown, just expressing your opinion, no harm there.
The reason I use A123's exclusively is not because of source voltage, but because of a 95% capacity discharge that is nearly FLAT at 6.6 volts and the fact that I need only use ONE charger, ever, and I can charge both ignition and RX batteries and leave 'em sitting for weeks, then go fly, and life is good.