Good point about some manufacturers putting a preferred connector on their "output" port, and I did that with UPP once too (but forgot about it). Your battery (960 wh 20 X 48) providing 50 miles seems about right for 18 - 20 mph under "normal" conditions (relatively flat terrain, 180 pound rider, little wind etc) since the "experts" state those conditions for a hub motor should require about 20 wh per mile.