Quantifying the state of the art of electric powertrains in battery electric vehicles: Range, efficiency, and lifetime from component to system level of the Volkswagen ID.3

Abstract

With the rise of battery electric vehicles to mass production, many technical improvements have been realized to drastically increase the electric range, efficiency, and sustainability. However, insights into those valuable state-of-the-art solutions are usually not shared with researchers due to the strict non-disclosure policies of electric vehicle manufacturers. Many studies, therefore, rely on assumptions, best-guess estimates, or insider knowledge. This article presents an in-depth multi-scale analysis of the electric powertrain characteristics of a Volkswagen ID.3 Pro Performance. The focus is set on the range, power, and lifetime perceivable by the user. Thorough experimental tests are performed from the battery cell to vehicle level, following the energy conversion from source to sink. Energy densities are determined at all levels and the absolute electric range is quantified under varying operating conditions. Power capability and efficiency is evaluated at cell level by quantifying the battery cell and pack performance with current rate tests in charge/discharge scenarios and impedance determination, as well as by determining powertrain energy conversion efficiency with in-vehicle measurements. Moreover, accelerated aging tests of the lithium-ion battery cells are performed with close to real-world conditions and projected to vehicle level, demonstrating that the lithium-ion battery pack achieves mileages outperforming the warranty information of the manufacturer under real-world operation. Overall, the results provide valuable insights into the current state of the art and can serve as a reference for automotive engineering in academia. Over 10 GB of lithium-ion battery cell, pack, and overall powertrain measurement data from the lab and real-world environment is available as open source alongside the article. • Teardown and multiscale investigation of the electric powertrain of a Volkswagen ID.3. • Battery module to pack integration leads to predominant energy density losses. • Powertrain efficiency is mainly limited by the inverter/electric machine unit. • Fast charging limitation is traced back to the power capability at cell level. • Aging tests indicate larger mileage/operating time as assumed in the literature.