How to charge 10s

Hi im doing a build and planing on using (4x) ZIPPY Flightmax 5000mAh 5S1P 20C so 2 in parallel and 2 series. how do i charge them without charging every battery individually? will it work with IMAX B6AC V2 Balance Charger? and do i need a BMS.

Yes you can charge them all at the same time , here is a video that will explain everything for you