electric bike battery

I have converted a full-suspension Kona Bike with a Motor from China 1500W. I built the wheel with strengthened spokes and rim. For controller and LCD I went to Greenlance from which I bought my 48V 20AH battery with Samsung Lithium-ion Cells 21700. The controller is universal for 48V - 72V...

Hi All, I'm looking for a decent Samsung 48V battery for my Bafang 750W motor, I would greatly appreciate it if some recommendations can be passed over.