A portable power bank controllable via inertial input. Control includes: while in one or both of a charge mode and a providing charge mode, monitoring for an inertial input; upon detection of a first active mode inertial input, activating the user visual display; upon detection of a second active mode inertial input disabling one or both of the output mode and the charge mode; and upon detection of a third active mode inertial input, re-enabling one or both of the charge mode and the providing charge mode.