Abstract: According to an example embodiment, a method is provided, the method comprising: determining a respective impedance curve for a plurality of cells extracted from a plurality of rechargeable batteries, wherein each impedance curve is descriptive of an internal impedance of the respective cell as a function of frequency over a predefined frequency range; determining, for each of the plurality of cells, respective one or more impedance characteristics based on the impedance curve determined for the respective cell; and sorting the plurality of cells into one or more quality classes in accordance with the one or more impedance characteristics determined for the plurality of cells.