Victron BMV-702 Grey Battery Monitor with Fuel Gauge

The Victron BMV-702 Battery Monitor in gray calculates state of charge from measured current, with a second configurable input.

Midpoint voltage monitoring is what that second input does best, and it catches a problem nothing else will. In a series-connected bank the midpoint reveals imbalance between batteries. A pack reading correctly overall can have one battery failing while another is being overcharged to compensate, and only the midpoint shows it.

The same input can instead monitor a second battery voltage or battery temperature, depending on what the installation needs. Temperature matters because charging voltage should change with it, and a second battery voltage covers a starter bank alongside the house.

Calculating state of charge from current flow rather than voltage is the fundamental difference from a voltmeter. Voltage under load says almost nothing about remaining capacity, and a voltmeter alone leads to unpleasant discoveries. Explore more battery monitoring.

• Midpoint monitoring reveals imbalance in a series bank
• One battery can fail while another overcharges
• The overall reading looks correct throughout
• Or monitor a second battery or temperature instead