Work

Lab-to-field gap in battery aging studies: Mismatch of operating conditions between laboratory environments and real-world automotive applications

Year: 2025

Type: article

Abstract: In response to the growing demand for electric vehicles, ensuring the longevity of traction batteries has become a central focusof scientific research. While most aging studies rely on accelerated aging testing with tightened stress factors, real-world batteryoperation reveals fundamentally different load profiles and aging conditions. To disclose the gap between the laboratory and thereal-world application, we collected and assessed almost 2600 stress factor combinations from 201 different calendar and cycleaging studies. Moreover, we gathered and analyzed vehicle data from over 72 000 km of everyday usage of seven vehicles inpublic road traffic in Germany and extracted the related battery-specific load spectra. The stress factor combinations chosen in theliterature show a trend towards high temperatures and state of charges (SOCs) during storage in calendar aging studies. In contrast,cycle aging tests are predominantly performed at full depth of discharge (DOD) or elevated average SOC levels, with current ratesof primarily ±1C at 25 ◦C or slightly elevated temperatures. Contrary to this, the field data analysis reveals the following mainfindings: Driving events rarely exceed 30 km in distance or 40 min in duration, with an average driving speed of 61.1 km h−1. Thisleads to average current rates of −0.2 C in discharging and 0.1 C in charging direction and average cycle depths of less than 30 %,while the average battery pack temperature ranges around 17 ◦C. Comparing laboratory test conditions with stress conditions infield applications reveals three major discrepancies: First, the stress levels applied are substantially higher than the stresses actingin real-world operation. Second, the dynamic load characteristic of real-world vehicle operation is rarely reflected; most studieswork with synthetic constant current load cycles. Third, intermediate rest periods, which are predominant in real-world use, areomitted in most studies.

Source: eTransportation

DOI: 10.1016/j.etran.2025.100518