The ATEN Professional Online UPS is a distinctive and innovative electrical device that provides backup power to a load when the input power source, or the mains, fails. The basic technology of an online UPS is the same as that of a standby or line-interactive UPS, but the ATEN Professional Online UPS provides a much higher current of AC-to-DC battery charger/rectifier, with the rectifier and inverter designed to run continuously with improved cooling systems.