... selector for charger can use both 110Vac and 220Vac.2,Efficiency: 85%-90%.3,Convection ... 4,Automatic,Advanced ,high frequency, switch mode design allows more efficient, faster charging.5,Also supply ... current, over voltage. over temperature, short circuit and reverse polarity protection.8,Led display charging states ... temperature:-10 - +60 . fast charging and maintenance free forklift battery charger