... Frequency50/60Hz±0.5Overload Capacity 120%(60S)Wave FormSine Wave THD3Transient response ±4%(100%Loading)Harmonic Distortion Less Than 3% at Linear loading(Full ... battery voltage,overload,other abnormities.LCD Status DisplayStatus of UPS,input voltage,input frequency,output voltage,output frequency,battery voltage,load Audible AlarmBuzzerAC unusual 4S/Battery low voltage ...