What is a VSR Voltage Sensitive Relay and How to install VSR? VSR for Dual battery system explained

VSR (Voltage Sensitive Relay), ACR (Automatic Charging Relay) or smart battery isolator are automatically controlled relay switches that allow two batteries to be combined when charging, and to be isolated when not charging and current is draining from one of the batteries. This way you can automatically preserve a fully charged battery at all time, especially the start battery for starting the engine. In the video is a typically wiring diagram from a VSR in a two Battery system (Start and House batteries). Normally the VSR senses voltage from the ENG (engine) port to decide whether it should close (make) or open (break) the connection, so if the Engine is ON the sensing voltage would be high and VSR will turn ON and make the connection – allowing BOTH Start and House batteries being charged. And when the Engine is OFF the voltage will drop and VSR will turn OFF by cutting the connection and this way the loads would draw powers from ONLY the house battery – preserving the full power capacity in the Start Battery. There are also more advanced features for the VSR like manual override, 0 power storage mode, external indication LED port, Dual port sensing or 12/24V input voltage support…etc. Please check our product introduction page for more information. YIS Marine VSR products visit our website at #taiwan