Battery Pack Design: Charging Parallel 18650s Through a Step Up Converter and BMS
A BMS - Battery Management System is equalizing voltage an each cell, while the cells are connected in series. There is no such BMS for parallel connected cells. 
However you can use your BMS if you wish, it would give a balance charge and overcharge/discharge protection (possibly, I don't know the BMS model). Rather using a step up converter you can change to step down converter and you're fine.