The BMS772 does the self balancing. You will need to control the overall current provided to charge the battery. You should also provide some power steering/isolation otherwise with the two batteries in parallel, the higher charged one will attempt to charge the lower charged one.
Also - what is not clear above - are you making one pack or two separate pluggable packs. You CAN parallel individual cells in one large one (and use a single BMS) if you wish, but that does not seem to be how you have described it. So one BMS per pack is needed.
The BMS is approximately the size of a 3S 4000mA/h hobby LiPo - Sorry i do not have exact dimensions.
we have a drone battery that consists of 2 x 7000mAh 6S lithium polymer batteries. These two packs are going to be connected in parallel to achieve 14000mAh 6S.
What I did is made a housing to incubate the two packs and connected them to a single 10 pin robust male connector and in the UAV size there is a female connector . The plan is to make the drone battery like cartridge so we can slide it in UAV to click in and go on and when battery need recharging we take out the cartridge and connect it to the charger with same pin type used on UAV. The question is are we able to use you BMS 772 to achieve a self balancing cartridge when recharging?
if so how would we do that? Do we need two boards or one only? And how to connect it to the batteries?
and what’s the dimensions of that board please?