... 90%AudibleAlarmBattery DischargeBeeping sound every 4 seconds after utility power failsBeeping sound every second if battery approaches final dischargeOverload ... 90%IndicatorsLCDVFD/LCD Indicator StatusInput/Output Voltage,Frequency,Output Power,Battery,Utility,Inverter,Overload,Fault,BypassCommunication PortRs232/USBInterfaceMonitor of ... 79.00 85.00 Online & Sine Wave Uninterruptible Power Supply(UPS)