What is a UPS? (Uninterruptible Power Supply) An Uninterruptible Power Supply is a device that is used to keep computers and equipment safe when there is a loss, or a significant reduction, in the primary power source. To achieve this, the UPS houses several batteries that take over when it detects a loss or reduction in available power. Once this is detected, the control is transfer over to the batteries, and via an inverter, the batteries DC voltage is converted into AC for the devices. The am