Information handling system external adapter and battery source

A method for powering a portable information handling system, the method comprising:

• removeably coupling an AC-to-DC adapter self-contained module directly to a controller self-contained module to form a contiguous unit, the controller self-contained module lacking an integrated power source capable of converting AC to DC power or of storing DC power, the AC-to-DC adapter lacking communication interfaces to an information handling system;
• applying AC power to the AC-to-DC adapter self-contained module;
• converting the AC power to DC power with the AC-to-DC adapter self-contained module;
• removeably coupling the controller self-contained module to a portable information handling system;
• controlling transfer of the DC power from the AC-to-DC adapter self-contained module to the portable information handling system with the controller self-contained module;
• and
• communicating a lack of the AC-to-DC adapter self-contained module to the portable information handling system from the controller self-contained module if the controller self-contained module couples to the portable information handling system without the AC-to-DC adapted self-contained module.

A portable information handling system power system comprising:

• a power controller integrated in an information handling system and operable to coordinate power transfer with an external power source;
• and
• an external power source having a cable to couple with the information handling system, the external power source having plural separate self-contained modules removeably coupled directly to each other to form a contiguous unit including at least a controller module and a separate power source module, the controller module operable to coordinate power transfer with the power controller for the power source to provide power routed through the controller module to the information handling system, the controller module lacking a capability to provide power unless coupled to a separate power source module, the controller module communicating a lack of a power source module to the power controller;
• wherein the power controller issues a warning at the information handling system if the controller module lacks an interface with a power source module.