Comparative Analysis of EV Battery Degradation: Real-World Data vs. Lab Simulations

This paper investigates discrepancies between electric vehicle (EV) battery degradation observed in real-world usage and predictions from lab simulations. While lab testing typically assumes consistent, full charge-discharge cycles under controlled conditions, real-world EV operation introduces variable charge states, sporadic Depth of Discharge (DoD), and temperature fluctuations due to driving behaviors such as acceleration and braking. Using real-world data from Stanford University [1] alongside lab simulation data, this study analyzes how these factors accelerate degradation in actual usage scenarios compared to lab predictions. Findings reveal that real-world factors significantly reduce battery lifespan and performance, challenging the reliability of lab-based models for predicting EV battery longevity. This work suggests adaptations in lab methodologies to incorporate variable State of Charge (SoC), DoD, and temperature fluctuations, which could improve the accuracy of battery management systems and extend practical battery life in EV applications.