摘要 |
The present invention is directed to monitoring battery cells. In accordance with various embodiments, a battery pack (110) having a plurality of battery cells (121) connected in series is monitored. Current is separately injected into individual ones of the plurality of battery cells (121), such as by operating a balancing circuit coupled across an individual cell (121), to inject current (e.g., positive or negative) into the cell. For each of the battery cells (121), an output is provided to indicate cell voltage of the battery cell (121) responsive to the current injected therein. An output indicative of current through each of the battery cells is provided as well. From the respective outputs as corresponding to each individual cell (121), amplitude and phase characteristics of the current and voltage outputs for each of the cells are extracted to provide an indication of an impedance characteristic of the cell(s). |