Charging-control apparatus and charging-control method

A charging control apparatus that controls a state of charge of a secondary battery installed in a vehicle by a regulator possessed by an alternator, the charging control apparatus comprising:

• a processor configured to:
• calculate an SOC indicating a state of charge of the secondary battery;
• perform a determination of whether the calculated SOC is greater than a predetermined threshold;
• and
• control the regulator in such a manner that, in a case where it is determined that the calculated SOC is greater than the predetermined threshold, a power generation voltage of the alternator comes to a low state, and in a case where it is determined that the calculated SOC is less than the predetermined threshold, a power generation voltage of the alternator comes to a high state, wherein
• the threshold has hysteresis, and the determination is based on a first threshold in a case where the SOC is decreasing and the determination is based on a second threshold which has a value greater than that of the first threshold in a case where the SOC is increasing;
• and
• the processor being configured to control the regulator in such a manner that, in a case where it is determined that the SOC increases and is greater than the second threshold, a power generation voltage of the alternator comes to a low state, in a case where it is determined that the SOC decreases and is less than the first threshold, a power generation voltage of the alternator comes to a high state, and in a case where it is determined that the SOC is between the first predetermined threshold and the second predetermined threshold, the power generation voltage of the alternator is maintained.