Representativeness of aging-experiment design for reused batteries

Assess whether aging experiments on reused batteries are representative of real second-life operation when current rates and state-of-charge ranges are specified using nominal rather than measured capacity, and determine how this experimental-design discrepancy affects observed degradation and aging-knee formation.

Background

The review observes that retired batteries often have lower actual capacity and higher resistance than their nominal specifications imply. Consequently, an experiment designed around nominal capacity may impose a higher effective current rate and a different effective state-of-charge range than intended. The paper identifies this discrepancy as a possible cause of artificially accelerated degradation and aging knees, making the representativeness of commonly used aging protocols an unresolved issue.

References

Accelerated aging and the appearance of knees in degradation curves may be caused by this experimental design problem. This raises a major question about the representativeness of battery aging experimentation design. Further investigation on this matter is necessary before concluding that battery reuse is not viable.

— Battery Second Life : A Review of Experimental Studies  (2610.11632 - Hassini et al., 8 Oct 2026) in Appendix, Section “Effect of accelerating factors”