No additional shunt bar required for under 50 amps. Monitor amperage from batteries, wind turbines, solar panels, inverters, generators, hydroelectric, and more.
About DC Volt Meters:
The positive and negative inputs are typically not marked on the DC Volt Meter. If you connect them to your battery and get a negative reading, simply swap the wires.
12 Volt battery systems should use a 15 Volt meter; 48 Volt systems should use a 70-75 Volt meter.