CONTROLLERS FOR UNINTERRUPTIBLE POWER SUPPLIES AND METHODS OF OPERATING THE SAME

An uninterruptible power supply (UPS) is operated to selectively provide energy to a critical load from a grid and an energy storage device and to transfer energy between the energy storage device and the grid. A controller causes the UPS to selectively support bidirectional and unidirectional transfers of energy between the grid and the energy storage device based on a state of charge (SOC) of the energy storage device.