Failure detection method and failure detection system for battery racks

A failure detection method for battery racks, performed by a failure detection system for battery racks comprising a voltage data retrieving module and a micro-controller, wherein the battery racks comprise multiple battery modules, and the failure detection method comprises:

• step (a) sensing a voltage data of battery cells of the multiple battery modules by the voltage data retrieving module, and continuously computing a voltage difference data of the voltage data in a computation frequency by the micro-controller;
• step (b) using the voltage difference data of the battery racks up to present to compute a standard deviation by the micro-controller;
• step (c) when determining that the standard deviation is greater than a preliminary threshold, respectively obtaining a first voltage trend according to the voltage difference data of a first period and a second voltage trend according to the voltage difference data of a second period, wherein the second period is greater than the first period;
• step (d) computing, by the micro-controller, an intersection of the first voltage trend and the second voltage trend to obtain a voltage trend state;
• step (e) computing, by the micro-controller, a voltage slope according to the voltage difference data of the second period;
• and
• step (f) when determining that the voltage trend state is at a potentially abnormal state and the voltage slope is greater than a slope threshold, generating an alarm message by the micro-controller, wherein the alarm message indicates that a position of the battery cells being at an overvoltage state corresponding to the voltage difference data when the standard deviation is greater than the preliminary threshold.