Influence of Cell Position on the Capacity of Retired Batteries: Experimental and Statistical Studies

TL;DR

This study investigates the performance of retired electric vehicle batteries, revealing high average capacity with significant variation, and finds that cell position within modules does not affect performance, emphasizing the importance of dispersion evaluation.

Contribution

The paper provides experimental and statistical analysis of retired battery performance, highlighting the independence of cell performance from position and the need for dispersion management.

Findings

Retired cells have an average of 95% capacity with 2.4% dispersion.

Cell performance is not affected by position within the module.

High performance variability suggests need for thermal management.

Abstract

Understanding how batteries perform after automotive use is crucial to determining their potential for reuse. This article presents experimental results aimed at advancing knowledge of retired battery performance. Three modules extracted from electric vehicles were tested. Their performance was assessed, and the results were analyzed statistically using analysis of variance (ANOVA). The 36 retired cells exhibited a high level of performance, albeit with significant variation. On average, the cells had a 95% state of health capacity with a dispersion of 2.4%. ANOVA analysis suggests that cell performance is not correlated with their position inside the module. These results demonstrate the need to evaluate dispersion within retired batteries and to develop thermal management and balancing systems for second-life batteries.