... less than 3% THD b).Double conversion designZero transfer/complete isolation of input AC c).UPS monitoring softwarePowerful ... itself off after ten seconds to conserve battery power when no power needs are detected. h).Battery level indicatorsLED' ... and vice versaLED indicatorsStatusLoad level/battery level, battery , utility power, inverter, bypass, overload, faultAudible alarmBypass, on battery mode, ...