As electric vehicles continue to evolve, 800V powertrains are becoming an increasingly attractive option. They enable faster charging, improved efficiency and better overall vehicle performance. However, achieving these benefits typically requires a dedicated 800V battery system, adding cost, complexity and integration challenges.
The BATSS project takes a different approach. Rather than relying on a dedicated high-voltage battery pack, BATSS has developed interleaved bidirectional DC/DC converter that enables many of the benefits of an 800V architecture while using a 400V battery system. This flexible approach provides vehicle manufacturers with greater design freedom while reducing the need for costly high-voltage battery packs.
The BATSS solution.
At the heart of the BATSS concept is a high-performance DC/DC converter that intelligently manages the flow of energy between the battery system and the vehicle’s high-voltage DC link. The converter dynamically adjusts voltage levels to delivering a variable DC-link voltage of up to 800V from a 400V battery system.
Its bidirectional operation enables efficient energy transfer during vehicle propulsion, regenerative braking and DC fast charging. Built around advanced wide-bandgap silicon carbide (SiC) semiconductor technology, the converter achieves higher efficiency, lower switching losses, increased power density, and more compact and lightweight power electronics solution.
More than a power converter.
The BATSS converter is designed to do far more than simply boost voltage. Its innovative interleaved architecture also enables active balancing between battery modules during normal vehicle operation. By continuously equalizing module voltages and state-of-charge levels, the converter improves overall battery utilisation and preventing weaker modules from limiting pack performance. At the same time, the interleaved topology minimises current ripple and thermal stress, contributing to higher overall system efficiency.
Designed with reliability and scalability in mind.
Performance is only part of the story. The converter architecture has been designed to improve the robustness and resilience of the entire battery system. Each battery module is connected through its own converter phase. Should a battery module develop a fault, it can be isolated while the remaining modules continue operating and compensate for the required voltage and power. This built-in fault tolerance improves reliability and enhances safety.
The distributed nature of the converter also offers excellent scalability. Additional battery modules and converter phases can be incorporated with minimal changes to the overall architecture, making the concept adaptable to vehicles with different power and energy requirements.
From prototype to future mobility.
To validate the technology, the BATSS consortium has developed a 60kW hardware prototype consisting of three bidirectional converter legs connected to independent battery modules. Operating at a switching frequency of 50kHz, the prototype will demonstrate efficient bidirectional power flow between 400V and 800V, active battery balancing and reliable operation under realistic testing conditions.
By combining advanced power electronics with an intelligent modular battery architecture, BATSS is redefining how the new generation of electric vehicles can be realised and ready for the mobility challenges of the future.
Stay tuned as BATSS continues to redefine what it means to build battery systems that are not only high-performing but also safe, circular, and ready for the future.
