Patent attributes
A variable power bus (VPB) cable, such as a USB Type-C cable, is validated for actual current capacity with respect to a specified power rating for the cable. The power cable validation is performed when the cable is connected to a power storage adapter and a portable information handling system. The validation includes, prior to negotiating a power delivery contract for electrical power to be supplied to the information handling system from the VPB port via the VPB cable, applying a first voltage to the VPB cable to identify a first indication of a current capacity of the VPB cable; and when the first indication confirms that the current capacity of the VPB cable corresponds to a specified power rating for the VPB cable, enabling the power delivery contract to be negotiated according to the specified power rating, otherwise blocking the power delivery contract using the VPB cable.