In an embodiment, a compact factory assembled and tested cabinet-based Direct Current (DC) power system includes at least one Alternating Current (AC) to DC converter disposed in a cabinet as at least one interchangeable module. An AC input section is also disposed in the cabinet and supplies AC power to the converter(s). At least one other electrical component is disposed in the cabinet, possibly as a module and it receives DC power from the converter(s). Other embodiments are also disclosed.