A vehicle battery diagnosis system diagnoses the state of use of a battery of a vehicle, and includes: an information accumulation portion that accumulates diagnostic information that includes a use condition regarding the battery; a control plan presentation portion that presents a plurality of control plans about the vehicle for increasing the service life of the battery on the basis of the diagnostic information; and an information changing portion that changes control information regarding the control of the vehicle which is retained in a vehicle-mounted ECU of the vehicle so that the control information corresponds to a control plan selected from the plurality of control plans.