1、Function: Just like having two separate power sources, the dual battery isolator kit allows your accessories to run on a separate battery when the engine is not running in the vehicle, while keeping the main battery charged. 2、Smart VSR Kit: The automatic 140A dual battery isolator can charge two battery systems. The VSR cuts off at 13.3 volts and at 12.8 volts to ensure your primary battery is always charged and ready to start your vehicle. 3、Complete Kit: No alternator or ignition connections are required, no need for any additional components to complete the installation, everything is included in the kit, including leads, connectors, screws, zip ties, and more. 4、Wide Application: Voltage sensitive relay kit can be widely used in various vehicles such as 12V 24V cars, trucks, RVs, ATVs, UTVs, boats, vans, SUVs, caravans, camping applications. 5、Professional Manufacturing: The manufacturing conforms to the standard specification, strictly follows the factory quality control, voltage sensitive relay kit can be used for a long time.