new type,pure sine wave INVERTER/CHARGER HBC-PSW1000VA, HBC-PSW2000VA, HBC-PSW3000VA, HBC-PSW4000VA, and ... : 50Hz±2% automatic stabilized frequencySwitching type: auto switch in 3sOutput wave form: sine waveEfficiency: ≥0.7Battery method: HBC is the external connected ... battery, us14.5-15V (other voltage is multiplied) new type,pure sine wave INVERTER/CHARGER,500VA TO 5KVA