... , 1/1, 1/3) Intelligent RS232 /RS422 Communication Port, Dry contactor SNMP adapter and C grade lightning proof inbuilt Green power ... is too large, expansion very difficult.ReliableBatteries connect with the DC power distribution, directly protect the load, safe and reliable.Exist ... maintenanceRemarkStandard products, low costSpare parts poor general, high cost. High DC Output Modular UPS Online