A 3-phase uninterruptible power supply (UPS) including first, second, and third AC/DC converters, a DC/DC converter, and at least one DC/AC converter coupled to multiple electrical buses. The first, second, and third AC/DC converters each being configured to receive AC power and to provide multiple DC signals to the multiple electrical buses. The DC/DC converter being configured to convert DC voltages present on the multiple electrical buses to a DC voltage that can be used to charge a battery. The DC/AC converter being configured to receive DC power from the multiple electrical buses and to provide an AC output. The 3-phase UPS being configured such that when suitable AC power is provided to the AC/DC converters, the DC/DC converter is configured to charge a battery, and when suitable AC power is not provided to the AC/DC converters, the DC/DC converter is configured to provide DC power to the multiple electrical buses using power provided by the battery.