Controlled Temperature Break-in Proposal for Batteries on Dynamometer Cycles: A Compliance Approach with SAE J1634 Standards

Given the recent increase in exhaust gas emission restrictions, electrification has become the major development focus in the transportation industry. Like combustion vehicles, electrified ones must also undergo homologation tests. According to the Battery Electric Vehicle (BEV) homologation standard, SAE J1634, the vehicle must be subjected to a minimum 1600 km break-in cycle. This standard also allows the battery to undergo an equivalent cycle that results in the same level of degradation. Since the recommended break-in cycle duration exceeds the vehicle’s battery autonomy, at least one recharge is necessary to accomplish the break-in normalization. This requirement implies more time allocated to a dynamometer, which represents additional costs to the manufacturer. As in any industry, cost reduction is crucial to enable the development of new technologies in the automotive industry. To contribute to this, a faster battery break-in cycle is proposed. As validated in several literature studies, degradation tends to increase at low and high temperatures. With this in mind, the present work aims to reduce the total battery break-in cycle by operating the storage device at different temperatures. To assess the proposal’s validity, an electric vehicle with a 23.8 kWh battery capacity and its respective degradation model are presented. The final State of Health (SoH) for the standard recommended break-in is calculated, and the proposed approach cycle conditions are determined by considering the equivalent degradation for one full cycle.