Quantify interconnect-resistance impact on measured internal resistance and heterogeneity

Determine the exact contribution of module interconnect resistances to the internal resistance values computed from Hybrid Pulse Power Characterization pulses for each series-connected Cell in Audi e-tron 4P3S battery modules when voltages are measured at the external connectors (C1+, C2+, C3+ relative to G−), and quantify how these contributions affect the observed intra-module resistance heterogeneity; additionally, verify whether geometry-dependent interconnect effects are a dominant factor in the measured resistance differences.

Background

Internal resistance was estimated for each Cell from HPPC pulses while voltages were measured at module external connectors referenced to ground. Under this configuration, the measured voltages include voltage drops across interconnects, which the authors cannot separate from the Cells’ terminal voltages in the present setup. As a result, the precise influence of interconnect resistances on computed internal resistance and on the observed heterogeneity across Cells remains undetermined.

The authors also argue that uniform interconnect resistances alone would not explain the observed pattern and suggest geometry-dependent interconnect effects are unlikely to dominate; however, this assessment cannot be conclusively verified with the current measurements, motivating a targeted study to quantify interconnect contributions and test their role.