To get more information about how our auxiliary battery is doing, we installed a DOC Wattson RV & Marine Battery Monitor and a Current Shunt Resistor. The monitor measures Amp-Hours, Kilo Watt-Hours, Amps, Watts, Peak Amps & minimum Voltage as well as Voltage.
The Amp hour (Ah) and Kilo Watt hour (KWh) measurements are much more accurate “fuel gages” than voltage measurements which depend on many other factors. Kilo Watt Hours are better than Amp hours because the effects of voltage change are included in calculating the actual energy delivered to the load. Ah and KWh are much more accurate than the voltage based RV or marine “Battery Indicator” measurements.
Peak Amps and minimum volts measurements show you even short duration load events and help you troubleshoot hard to find electrical problems. Statistics are reset when power is removed.