This meter keeps track of current flowing in and out of a battery bank and uses a sophisticated algorithm to read out the state of charge of the battery in Percentage Remaining and Amp Hours Remaining. It also displays Volts and Amps, time to go, and Consumed Energy and keeps track of Historic Data including Battery Efficiency, Average Discharge, Deepest Discharge, Number of Cycles, Overvoltage, and Undervoltage Alarms.