12V 140A Automatic Dual Battery Isolator Voltage Sensitive Relay Kit

This 12V 140A automatic dual battery isolator kit is a voltage sensitive relay for managing charge sharing between a vehicle's starter battery and a separate auxiliary or leisure battery. It monitors system voltage and automatically connects both batteries when a charging source is present, then separates them when voltage drops, allowing the alternator to charge the auxiliary battery while reducing the risk of the starter battery being discharged by connected accessories.

Features

• Automatic linking of starter and auxiliary batteries during charging


• Automatic isolation when charging stops


• Dual-sensing operation when either connected battery is receiving charge


• Primary-battery-priority charging operation


• Helps prevent auxiliary loads from draining the starter battery


• No manual switching required


• LED status indication


• Surge protection for connected electronics


• Compact format for vehicle and leisure battery installations

Specifications

• System voltage: 12V DC


• Continuous current rating: 140A


• Intermittent current capacity: 170A


• Cut-in voltage: approximately 13.3V


• Cut-out voltage: approximately 12.8V


• Switching delay: approximately 5 seconds


• Operating temperature range: -30°C to +105°C


• Ingress protection rating: IP65


• Control type: MCU-controlled voltage sensitive relay


• Dimensions: approximately 67.5 x 67.5 x 53.5mm


• Weight: approximately 200g

Installation Notes

• Intended for suitable 12V charging systems


• Compatibility with smart or variable-voltage alternators should be checked before installation


• Compatibility with lithium battery systems should be checked before installation


• Correct cable sizing and suitable circuit protection should be used for the application