BMS

I have a 48 volt LiFePO4 battery pack. Board is smashed. I have Google-ed BMS and Lithium Iron battery packs and can't find a replacement board. I am using a battery charger for charging Ni Cad battery pack till I get to proper voltage. It is battery charger from QST in the 70's and it good for Ni Cad, but Lithium is to be charged with the proper charger Constant voltage tapering current. I just ordered a new battery pack from eBay and hope it is better-er quality. My bike uses a 1000 watt front hub motor and I think it is supposed to use a 40 AH pack but maybe a twenty AH pack will be OK for a short ride. Are all or most battery packs from China using same BMS with lots of skinny wires and three big wires?
I will post my mountain bike pictures on EV page in future after a decent test ride.