Li-Po battery packs usually gets balanced really slowly so I made the Charging thru the Balance board connector (JST connector) for Deans type battery plug. Similar can be made for XT60 connectors. The idea is to charge the battery almost full until it starts to balance charge the unbalanced Cells. At this point you Stop charging and Start Charging every cell individually until they are full. The cable supports 1 Cell at once and it’s made for 3s (3 Cell) Lithium-Ion Polymer battery pack.