Information handling system interrupting current to external module if current exceeds different current limits when handling system receives current from battery and alternating current source

A portable information handling system (IHS) includes an external module which derives its power from the internal unregulated DC power rail of the IHS. An IHS power subsystem includes a multiple threshold current protection circuit which continuously monitors power usage by the external module. The multiple threshold current limit protection circuit dynamically adjusts the current limit depending on whether the IHS is powered by an AC source or a DC battery source.