Patent ID: 8866444

Claim:
A fault-detection apparatus for a charging system that charges a collection of interconnected battery cells, the apparatus comprising: a) a data-acquisition system for receiving a set of data parameters from the collection while the charging system is actively charging the collection; b) a monitoring system evaluating said set of data parameters to identify a set of anomalous conditions; and c) a controller comparing said set of anomalous conditions against a set of predetermined profiles indicative of an internal short in one or more cells of the collection, said controller establishing an internal-short state for the collection when said comparing has a predetermined relationship to said set of predetermined profiles, wherein the set of data parameters is measured during a charge cycle that begins with V<V max and deltaT<(deltaT) max , wherein deltaT is a maximum difference in temperature between the cells throughout the collection and an ambient temperature, wherein (deltaT) max is a maximum acceptable difference in temperature that affects a change in voltage or current during charging, (deltaT) max being determined through testing and contained in a look-up table, and wherein the controller verifies that a charge current has not decreased or been interrupted, and that no additional load has been introduced, before establishing the internal-short state.