Method and device for detecting abnormality of lithium battery, battery management system, and battery system

A device for detecting abnormality of a lithium battery, comprising:

• a processor, configured to obtain a state of charge (SOC) value of the lithium battery in a charge process, wherein the SOC value is a ratio of a remaining capacity of the battery to a nominal capacity of the battery;
• change a value of a charge current at a time point corresponding to an arbitrary SOC value, and obtain a response signal within a time period of maintaining the changed charge current;
• and
• determine, based on response signals at time points corresponding to a plurality of SOC values, whether the lithium battery is abnormal;
• wherein the response signal is a voltage signal;
• the determining, based on response signals at time points corresponding to a plurality of SOC values, whether the lithium battery (102) is abnormal comprises:
• obtaining a first voltage value in an Nth voltage signal at a start time point of a first preset duration, and obtaining a second voltage value in the Nth voltage signal at an end time point of the first preset duration, wherein the first preset duration is an arbitrary time period within the time period of maintaining the charge current changed each time;
• obtaining an Nth voltage variation value based on an absolute value of a difference between the first voltage value and the second voltage value in the Nth voltage signal;
• and
• determining, based on the voltage variation value, whether the lithium battery (102) is abnormal.