Effect of electric vehicle battery voltage (400 Volt or 800 Volt) on charging technology

Abstract

With the growth and advancement of electric vehicles (EVs) there has been a sharp focus on the limitations of traditional 400 V battery systems, especially growing focus and demand for ultra-fast charging and advanced ways to tackle the challenge of ultra-fast charging as well as thermal efficiency. This thesis focuses on a review of current technologies and options as well as the technical impact of transitioning from 400 V to 800 V architectures in EVs. The thesis emphasizes how an increase in system voltage impacts infrastructure, charging technology, vehicle performance, and power electronics. A comparative analysis highlights the inefficiencies of 400 V systems at high power levels due to excessive current and thermal stress, while 800 V platforms demonstrate faster charging times, reduced resistive losses, and compatibility with emerging high-power DC fast chargers. Key enabling technologies, including onboard DC-DC converters, SiC-based inverters, and advanced cooling systems, are examined to assess the practical requirements for implementing 800 V systems. The thesis also focuses on currently available options and real-world applications in modern EVs by manufacturers as well as evaluating the adaptability of dual-voltage charging infrastructure. Towards the end, the study considers the future prospects and current barriers associated with emerging 1200 V platforms, focusing on insulation limitations and connector standards. Overall, the research highlights how traction battery architectures help make future EV charging strategies possible and share guidance on building efficient, scalable systems for an electrifying mobility sector.