To provide a power source unit for an motor-driven vehicle, which can shorten refresh discharge time when the same current as the conventional refresh discharge current is made to flow, and reduce refresh current, miniaturize a discharger, and realize cost reduction when a discharge time is made approximate to the conventional value, by setting refresh discharge start timing.

This power source unit for an motor-driven vehicle performs refresh discharge, in which discharge is continued until a battery voltage falls down to a specified refresh end voltage when the state of application of a charging battery reaches a specified condition. The power source unit is equipped with a battery management control part 117, which functions as an application pattern classifying means which monitors the state of application of the batter and classifies the state into prescribed patterns of application, and a judging means for judging whether refresh discharge is necessary based on the classified patterns of application.