POWER SUPPLY APPARATUS, HEALTH MONITORING METHOD THEREFOR, AND STORAGE SYSTEM INCLUDING THE SAME

A power supply apparatus may include a charging circuit configured to receive an external voltage and to generate a charging voltage by charging and discharging energy by switching according to a level of the charging voltage; an auxiliary power circuit configured to store an electric charge using the charging voltage; and a health monitoring circuit configured to determine a charging health state of the auxiliary power circuit by counting a number of switchings of the charging circuit during an interval in which the charging voltage rises to a first level from a second level, the determined charging health state being based on the number of switchings.