Here's my finished bike and stats:
POWER: 48V 10Ah SLA (4 x 12V 10Ah SLA BB Batteries)
MOTOR: 36V 500W rear "Goldenmotor" hub motor
CONTROLLER: 48V 600W Shenzhen (ecrazyman)
ACCESORIES: Watt's Up Meter, bike bell
TOTAL WEIGHT: 95 lbs
RANGE: 20-25 km (full throttle, some hills)
TOP SPEED: 40-45 km/h (flat ground, no wind)