Abstract: A deterioration degree estimation device includes an internal resistance detection unit, a deterioration management unit and a deterioration degree estimation unit. The internal resistance detection unit detects an internal resistance of a battery. The deterioration management unit manages a cycle deterioration of the battery. The deterioration degree estimation unit estimates a deterioration degree of the battery as an estimated deterioration degree based on an increase rate of the internal resistance. The deterioration degree estimation unit estimates the estimated deterioration degree such that the estimated deterioration degree decreases as the cycle deterioration increases, or such that the estimated deterioration degree increases as the cycle deterioration degree decreases.

Abstract: A deterioration degree estimation device includes an internal resistance detection unit, a deterioration management unit and a deterioration degree estimation unit. The internal resistance detection unit detects an internal resistance of a battery. The deterioration management unit manages a cycle deterioration of the battery. The deterioration degree estimation unit estimates a deterioration degree of the battery as an estimated deterioration degree based on an increase rate of the internal resistance. The deterioration degree estimation unit estimates the estimated deterioration degree such that the estimated deterioration degree decreases as the cycle deterioration increases, or such that the estimated deterioration degree increases as the cycle deterioration degree decreases.

Abstract: A fault diagnostic system (1) of the present invention includes a first fault diagnostic device (3) and a second fault diagnostic device (5). The first fault diagnostic device (3) acquires the voltage value of a battery (2) in accordance with a synchronization signal, and sends the voltage value and the synchronization signal. The second fault diagnostic device (5) acquires the voltage value of an inverter (4) in accordance with the received synchronization signal, matches the acquisition timings of the voltage value of the battery (2) and the voltage value of the inverter (4) on the basis of the received synchronization signal, and performs a fault diagnosis by comparing these voltage values.

Abstract: A fault diagnostic system (1) of the present invention includes a first fault diagnostic device (3) and a second fault diagnostic device (5). The first fault diagnostic device (3) acquires the voltage value of a battery (2) in accordance with a synchronization signal, and sends the voltage value and the synchronization signal. The second fault diagnostic device (5) acquires the voltage value of an inverter (4) in accordance with the received synchronization signal, matches the acquisition timings of the voltage value of the battery (2) and the voltage value of the inverter (4) on the basis of the received synchronization signal, and performs a fault diagnosis by comparing these voltage values.