A portable power unit is used for powering a rack-mountable equipment module, in which the equipment module includes an equipment chassis and a bus bar connector extending from the equipment chassis, and in which the bus bar connector is configured to engage a power distribution system of an equipment rack when the equipment module is mounted in the equipment rack. One aspect is directed to a portable power supply unit generally including a bus bar adapter electrically connected to a DC power supply, a mount for supporting the bus bar adapter, the mount having an end, and a tool-less connection electrically connected to the bus bar adapter and extending from the end of the mount, in which the tool-less connection is configured for engaging the bus bar connector of the equipment module.