Aspects of the disclosure include a system comprising at least one energy-storage-device connection, a first output connection to be coupled to a main power source providing main power, a second output connection to be coupled to at least one load, a first and second power converter coupled to the at least one energy-storage-device connection, and at least one controller coupled to the power converters and being configured to control the system to connect the power converters to the output connections, control the system to disconnect the first power converter from the second output connection responsive to detecting a fault in the main power, control the first power converter to provide power to the first output connection responsive to detecting the fault in the main power, and control the system to disconnect the second power converter from the first output connection responsive to detecting the fault in the main power.