A Simplified Electric Vehicle Battery Degradation Model Validated with the Nissan LEAF e-plus 62-kWh

Validated degradation models are needed to ensure optimized operation of battery systems. This paper presents a simplified electric vehicle battery degradation model, which estimates the degradation based on vehicle usage daily values. The model quantifies calendar and cycle degradation based on battery temperature, State-of-Charge and odometer. The model results are compared against two datasets of 2.5 years obtained with a LEAF e-plus: on-board State-of-Health readings retrieved from the battery management system and capacity estimations assessed while monitoring battery full recharges. The results show that, after 2.5 years, the model is well-aligned with the capacity estimations, while the on-board readings estimate the State-of-Health 1.3% lower. The obtained State-of-Health from the model after 2.5 years is equal to 95.6%, with calendar degradation being the major driver for the degradation cumulated so far.