I have paralled 2 EVC, what is the work principle/work logic for the them?

Please refer to below:
1. When primary charger or second charger works alone, they can use full PV energy and remaining load capacity.
2. When primary cahrger and second charger work together, the primary charger will allocate the PV energy and remaining load capacity for two chargers.
Note: the allocation ratio will not be that accurate due the allocated energy unbalance, it is to keep the system work stable, so it is normal.