<p>Description VSR 12V 140A Dual Battery Voltage Sensitive Relay Motorhome Camper INSTRUCTIONS SMART BATTERY ISOLATOR: The Dual Battery Isolators\/Voltage Sensitive Relays have been specially designed for a wide variety of 12V applications. Dual battery isolators sense the generated input voltage and automatically connect/disconnect the device or circuit at preset voltages, eliminating the possibility of discharging the main starting battery. Built with a weatherproof body (IP65) and durable silver tip contacts. The dual battery isolators also feature surge protection and an LED indicator designed to alert you when the unit is engaged. Dual battery isolators are ideal for dual battery setups as they allow two batteries to be charged at the same time and then isolate the batteries from each other when the vehicle is turned off, ensuring the starter battery is always charged and ready for use . FEATURES: - Designed for dual battery systems - Suitable for most 12V charging systems - Overvoltage protection - Easy to install - Automatic detection of main battery voltage level - Cut-off voltage: 13.3V - Cut-off voltage: 12.8V - Emergency charging function Package content: 1 x split load relay with hardware mounting kit. Notes: The black wire in the VSR should be connected to the ground/negative of the battery, the yellow wire in the VSR is for emergency charging (forced charging from the starter battery to the leisure battery, regardless of the voltage of starting battery is higher or lower than 12.8V), you can also leave it alone if you don't want emergency charging function.</p>