A power manager (300, 400, 550) comprising: - a DC power bus (305, 410); - a plurality of device ports (120a, 120b, 330a, 330b, 1 - 6) operably connectable to the DC power bus (305, 410); - a unidirectional DC to DC input power converter (3065, 510) having an input side and an output side disposed between the DC power bus (305, 410) and a first input device port (330a, 4) wherein an input side of the unidirectional DC to DC input power converter (3065, 510) is connected to a first input device port (330a, 4) and an output side of the unidirectional DC to DC input power converter (3065, 510) is connected to the DC power bus (305, 410); - a first unidirectional DC to DC output power converter (3070, 440) having an input side and an output side disposed between the DC power bus (305, 410) and a first output device port (120a, 2) wherein the output side of the first output power converter (3070, 440) is connected to the first output device port (120a, 2) and the input side of the first unidirectional DC to DC output power converter (3070, 440) is connected to the DC power bus (305, 410); - a first universal power channel (310a, 412) extending between the output side of the first unidirectional DC to DC output power converter (3070, 440) and the first input device port (330a, 4); and - a first controllable switch (315a, 482) disposed along the first universal power channel (310a, 412) between the output side of the first output power converter (3070, 440) and the first input device port (330a, 4); a second controllable switch (1025, 505) disposed between the first input device port (330a, 4) and the input side of the unidirectional DC to DC input power converter (3065, 510); a third controllable switch (320, 480) disposed between the output side of the first unidirectional DC to DC output power converter (3070, 440) and the first output device port (120a, 2); an electronic controller and a digital data memory in communication with the electronic controller, the electronic controller in communication with each of the unidirectional DC to DC input power converter (3065, 510), the first unidirectional DC to DC output power converter (3070, 440), the first controllable switch (315a, 482), the second controllable switch (1025, 505) and the third controllable switch (320, 480) and wherein the power manager (300, 400, 550) is operable to connect an external DC power device connected to the first input device port (330a, 4) to the DC power bus (305, 410) over the unidirectional DC to DC input power converter (3065, 510) or over the first unidirectional DC to DC output power converter (3070, 440) by operation of the first, the second, and the third controllable switches (315a, 482, 1025, 505, 320, 480). - a DC power bus (305, 410); - a plurality of device ports (120a, 120b, 330a, 330b, 1 - 6) operably connectable to the DC power bus (305, 410); - a unidirectional DC to DC input power converter (3065, 510) having an input side and an output side disposed between the DC power bus (305, 410) and a first input device port (330a, 4) wherein an input side of the unidirectional DC to DC input power converter (3065, 510) is connected to a first input device port (330a, 4) and an output side of the unidirectional DC to DC input power converter (3065, 510) is connected to the DC power bus (305, 410); - a first unidirectional DC to DC output power converter (3070, 440) having an input side and an output side disposed between the DC power bus (305, 410) and a first output device port (120a, 2) wherein the output side of the first output power converter (3070, 440) is connected to the first output device port (120a, 2) and the input side of the first unidirectional DC to DC output power converter (3070, 440) is connected to the DC power bus (305, 410); - a first universal power channel (310a, 412) extending between the output side of the first unidirectional DC to DC output power converter (3070, 440) and the first input device port (330a, 4); and - a first controllable switch (315a, 482) disposed along the first universal power channel (310a, 412) between the output side of the first output power converter (3070, 440) and the first input device port (330a, 4); a second controllable switch (1025, 505) disposed between the first input device port (330a, 4) and the input side of the unidirectional DC to DC input power converter (3065, 510); a third controllable switch (320, 480) disposed between the output side of the first unidirectional DC to DC output power converter (3070, 440) and the first output device port (120a, 2); an electronic controller and a digital data memory in communication with the electronic controller, the electronic controller in communication with each of the unidirectional DC to DC input power converter (3065, 510), the first unidirectional DC to DC output power converter (3070, 440), the first controllable switch (315a, 482), the second controllable switch (1025, 505) and the third controllable switch (320, 480) and wherein the power manager (300, 400, 550) is operable to connect an external DC power device connected to the first input device port (330a, 4) to the DC power bus (305, 410) over the unidirectional DC to DC input power converter (3065, 510) or over the first unidirectional DC to DC output power converter (3070, 440) by operation of the first, the second, and the third controllable switches (315a, 482, 1025, 505, 320, 480).