This new version of the charging board allows you to charge or discharge up to 4x 1S batteries at the same time using your charger (not included). You can change the cell count with the provided jumper (V1 would only allow to charge 4 batteries at the same time).
The charger will see the cells in series (i.e. charging 4 batteries will make the charger see a 4S battery with the capacity of a single cell). Note this is not the same as parallel charging.