The features of a DRT spectrum are considerably narrower than the discernible features in EIS raw data. By transforming the EIS spectrum of a battery to the relaxation time domain, inner processes become visible as peaks at their respective time constant τ or, equivalently, frequency f = (2πτ ) -1 . While these peaks, or modes, cannot always be clearly separated, they still give important hints about the number of contributing processes, their time scales, and their relative impact on the impedance of the battery. Shifts of these peaks can indicate changes of the internal battery chemistry.