Power supply device, and control method for power supply device

A power supply device, comprising:

• a storage circuit including a first node connected to a power supply, a second node that is grounded, a third node between the first node and the second node, and an electrical double layer capacitor between the first node and the second node;
• a charge circuit connected to the first node and configured to charge the storage circuit;
• and
• a power supply controller configured to measure a voltage at the first node and a voltage at the third node, and control the charge circuit, wherein
• the power supply controller performs a procedure of causing the charge circuit to charge the storage circuit and computing a first capacitance value and a first equivalent series resistance value based on the voltage measured at the first node and the voltage measured at the third node, in response to determining that a stop period is longer than a threshold period.

A control method for a power supply device including a storage circuit including a first node connected to a power supply, a second node that is grounded, and an electrical double layer capacitor between the first node and the second node;

• a charge circuit connected to the first node and configured to charge the storage circuit;
• and a discharge circuit connected to the first node and configured to discharge the storage circuit, the control method comprising:
• performing, when a stop period of an engine is longer than a threshold period, a procedure of causing the charge circuit to charge the storage circuit and computing a first capacitance value and a first equivalent series resistance value based on a voltage measured at the first node;
• and
• performing, when the stop period of the engine is shorter than or equal to the threshold period, a procedure of computing a second capacitance value and a second equivalent series resistance value of the electrical double layer capacitor based on the voltage at the first node while discharging the storage circuit by the discharge circuit.