The Voltage Sensing Relay (VSR) allows the charging of a second battery from a single charging source. When the voltage on the start battery rises to a level indicating a 60% charge, the VSR engages allowing the 2nd battery to charge.
When charging stops and voltage falls, the VSR will disengage isolating the two battery banks from each other. Dual sensing functionality enables the sensing of two battery banks allowing two way charging.

710-140 A features

• Safely charge two or more indipendent battery banks from one charge source (alternator, battery charger….)
• Protects start batteries from becoming flattened by domestic loads
• Simple to install 3-wire connection, leaves alternator wiring intact
• No Volt drop vs. diode isolators
• Zero stand by current draw
• Multi voltage, auto selects between 12 and 24V DC operation
• Ignition protected
• Surface or panel mountable

It replaces previous models 710-125A and 710-125A-DS