I make up my own battery packs from Duracell 2400 mah NIMH batteries. I can fly all day on a charge.
For info, my G90 is in a 9lb. Edge 540 64" ws. It has more than enough power for the Edge. I'm using the Slimline inverted muffler on it.
My only complaint with this engine, is that the carb keeps falling off. I've put it back on and retightened it at least 4 or 5 times. I've ordered a new carb adapter and carb retainer. the original one looks pretty deformed from all that retightening. I'm not sure why this started happening, but it seems to me thst a carb this big should be held on with something more substantial than a little 1/8 shaft.