BEP Dual Operation VSS Switch Cont Motorized - 12V - 275A [701-MDVS]Dual Operation VSS Switch Cont Motorized 12V 275A This Voltage Sensitive Switch (VSS) automatically senses connected battery bank voltage and provides optimal, efficient charging of the second bank. The VSS allows for independent battery banks to be combined or isolated based on the presence of a charging source (such as an engine alternator or battery charger), while also offering remotely activated, high current, emergency parallel connection.