METHOD FOR DIAGNOSING FAILURE OF CURRENT BREAKING DEVICE AND ENERGY STORAGE APPARATUS

A method for diagnosing failure of a current breaking device A included in a power supply system of a vehicle includes: a supply step of supplying power to a first electric load and a first energy storage apparatus by a power supply apparatus a command step of commanding the current breaking device A to perform cutoff while power is supplied from the power supply apparatus to the first electric load and the first energy storage apparatus and a determination step of measuring a charge current of a secondary battery A by a current sensor B while the cutoff is commanded to the current breaking device A, and determining presence or absence of failure of the current breaking device A based on a measured current value.