Design of an embedded hardware platform for cell-level diagnostics in commercial battery modules

TL;DR

This paper presents a hardware platform for non-invasive, cell-level diagnostics within battery modules, enabling detailed aging analysis and maintenance without disassembly.

Contribution

It introduces a novel embedded testing system that monitors and controls individual cells in fully assembled battery modules, ensuring safety and accuracy.

Findings

Cell voltage imbalances are constrained within reference values.

The platform enables safe, simultaneous cell screening in assembled modules.

Provides insights into internal heterogeneity for battery management.

Abstract

While battery aging is commonly studied at the cell-level, evaluating aging and performance within battery modules remains a critical challenge. Testing cells within fully assembled modules requires hardware solutions to access cell-level information without compromising module integrity. In this paper, we design and develop a hardware testing platform to monitor and control the internal cells of battery modules contained in the Audi e-tron battery pack. The testing is performed across all 36 modules of the pack. The platform integrates voltage sensors, balancing circuitry, and a micro-controller to enable safe, simultaneous cell screening without disassembling the modules. Using the proposed testing platform, cell voltage imbalances within each module are constrained to a defined reference value, and cell signals can be safely accessed, enabling accurate and non-invasive cell-level state-of-health assessments. On a broader scale, our solution allows for the quantification of internal heterogeneity within modules, providing valuable insights for both first- and second-life applications and supporting efficient battery pack maintenance and repurposing.