FAILURE DIAGNOSIS CIRCUIT, POWER SUPPLY DEVICE, AND FAILURE DIAGNOSIS METHOD

摘要

A failure diagnosis circuit is provided with: a voltage detection unit that detects a terminal voltage of an electricity storage unit; a current detection unit that detects a current flowing in the electricity storage unit; a SOC calculation unit that calculates a SOC of the electricity storage unit on the basis of the current detected by the current detection unit; a charging stopping unit that stops charging of the electricity storage unit when the SOC calculated by the SOC calculation unit reaches a preset determination value; and a failure detection unit that determines that a failure has occurred in the voltage detection unit when a variation of the terminal voltage, which is detected by the voltage detection unit, after the charging is stopped by the charging stopping unit differs from a predicted variation when the SOC of the electricity storage unit is at the determination value.