Provided are a vehicle-use energy storage apparatus, a vehicle-use discharge system, a discharge control method, and a vehicle-use energy storage device each capable of ensuring a sufficient amount of electricity as an amount of electricity used during a normal use time while ensuring an amount of electricity which is reserved as spare electricity, and possessing a sufficient charge-discharge cycle. According to an aspect of the present invention, there is provided a vehicle-use energy storage apparatus including an energy storage device having a negative electrode including a negative active material which contains: a first active material made of a carbon material; and a second active material having a higher oxidation potential than the carbon material and having a higher capacity per volume than the carbon material. In performing discharging of the energy storage device, a main discharge reaction occurs in the first active material during a normal time, and the main discharge reaction occurs in the second active material during an emergency time.