This vehicle drive device is provided with: a motor that directly drives the vehicle; a high-voltage first electricity storage device configured from a plurality of secondary battery cells; an electricity storage control device that monitors the charge/discharge state of the first electricity storage device; a DC-AC power conversion device that supplies DC power supplied from the first electricity storage device to the motor as AC power; a plurality of auxiliary machines provided to the vehicle; a low-voltage second electricity storage device that supplies DC power for driving the plurality of auxiliary machines; a DC-DC power conversion device that converts and supplies to the second electricity storage device the DC power of the first electricity storage device; and a vehicle control device that controls the vehicle overall. The vehicle control device is provided with: a degradation determination unit that judges whether the degree of degradation of the first electricity storage device is a determinable state; an auxiliary machine selection unit that selects at least one auxiliary machine from the plurality of auxiliary machines; and a degradation estimation unit that estimates the degree of degradation of the first electricity storage device by driving the auxiliary device selected by the auxiliary device selection unit when the degradation determination unit has judged the degree of degradation of the first electricity storage device to be determinable.
