... reverse connection.6. Unique Digitalt Meter Display: Indicating charging voltage, current, battery capacity (percent and AH) and charger status (timer, pre-charge ... )InputVoltage100~120VFrequency57~63HzProtectionBattery ReverseYes, Automatic ShutdownShort CircuitYes, Automatic ShutdownOverload Yes,Current LimitedCooling Fan Speed Controlled by Charging StageMechanicalDimensions 152*70*275mmWeight ...