ESTIMATION APPARATUS, ESTIMATION METHOD, AND COMPUTER PROGRAM

An estimation apparatus estimates an internal state of an energy storage device having a positive electrode, a negative electrode including a negative active material that contains SiO, and a nonaqueous electrolyte, the energy storage device changing from a positive-electrode limiting type, in which a discharge capacity is limited by the positive electrode, to a negative-electrode limiting type, in which the discharge capacity is limited by the negative electrode. The estimation apparatus estimates the internal state of the energy storage device by using a voltage value and an energization amount in a predetermined voltage range of the energy storage device or at a predetermined measured voltage value, or based on information on the shape of a discharge curve of the energy storage device.