Performance Assessment of a Second-Life Li-Ion Bess for EV Charging

Sergio, Lucas Augusto Zanicoski, Oliveira, Aline Kirsten Vidal, Hohmann, Matheus, Martins, Giuliano Luchetta, Naspolini, Helena Flávia, Rüther, Ricardo

ISES Solar World Congress 2025 · Fortaleza, Brazil · 2025-11-03
Published by International Solar Energy Society (ISES)
DOI: 10.18086/swc.2025.06.26

Abstract

This study presents the performance assessment of a second-life Li-ion Battery Energy Storage System (BESS) used in a real-world solar carport for electric vehicle (EV) charging. The system repurposes lithium-ion modules from 2012 Nissan Leaf vehicles, with State of Health (SoH) between 60% and 75%. While IEC 62933-2-1 provides standardized procedures for controlled performance testing, this study proposes a complementary method that identifies valid cycles from regular system operation, avoiding interruptions and better reflecting the BESS usage. Key performance indicators such as DC-side Round-Trip Efficiency (RTE), Depth of Discharge (DoD), and voltage difference among cells were analysed. Preliminary results from 113 EV charges show over 2.18 MWh provided to electric cars, with 80% sourced from PV and battery. This paper provides practical insights into second-life Li-ion batteries (SLBs) performance and testing under realistic conditions.

Keywords

Battery Energy Storage System (BESS), Second-life batteries, Performance Assessment

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