BACKUP POWER SUPPLY AND METHOD FOR DETECTING STATE OF HEALTH OF BATTERY

Embodiments of this application disclose a battery system and a method for detecting a state of health of a battery. The battery system includes a processing module and a plurality of battery modules. Each of the plurality of battery modules includes a battery management system and an electrochemical cell pack controlled by the battery management system. The processing module is configured to control the electrochemical cell pack in each of the plurality of battery modules to alternately perform discharging and charging operations. A sum of power of battery modules other than a first battery module in the plurality of battery modules is greater than power required by a target power-supplied object, and the first battery module is any one of the plurality of battery modules. A battery management system in the first battery module is configured to record a target time. The processing module or the battery management system in the first battery module is configured to determine a state of health of the electrochemical cell pack in the first battery module based on the target time. In the embodiments of this application, a state of health of each of the plurality of battery modules can be detected, thereby improving accuracy of detecting the state of health of the battery.