47 Battery Show USA | Show report Beyond cooling, the fluid plays a critical role in system safety and compatibility. Lubrizol evaluates multiple parameters to tailor formulations for specific customer needs: “We consider viscosity, thermal conductivity, density and specific heat capacity to optimise heat transfer. Compatibility with materials like hoses and gaskets, anti-corrosion properties and resistance to water ingress are essential.” Evogen thermal-management fluids also soften the impact of thermal events. In experiments comparing air-cooled batteries to immersioncooled ones, “we observed a dramatic reduction in flaming particles and heat dispersion with our fluids”, says Guo. This reinforces the fluid’s ability to control overheating and limit thermal damage to adjacent cells. Adopting immersion cooling requires a significant shift in EV battery pack manufacturing, including capital investments and process changes. However, Guo explains that Lubrizol is collaborating with OEMs, demonstrating the benefits of immersion cooling and helping them to improve reliability and safety. Stafl Systems showcased its nextgeneration BMS, designed to elevate safety, accuracy and efficiency in diverse e-mobility applications. Building on its extensive experience across electric aviation, marine and heavy equipment sectors, BMS2000 is a complete overhaul of its predecessor, the BMS1000. “The BMS2000 represents a full refresh of both hardware and software,” says Stafl Systems’ Erik Stafl. He says Stafl Systems has integrated the latest analogue sensing and microcontroller technology, using a new safety-critical software architecture and several new battery pack sensors. At its core, the BMS2000 uses Analog Devices’ sixth-generation ADBMS6830 front-end circuitry, providing highly accurate and redundant voltage and temperature measurements. This supports functional safety certifications up to ASIL-D, the highest automotive safety standard. “Redundancy and accuracy are crucial for high-reliability systems, allowing time-correlated cell voltage and current measurements within one microsecond,” Stafl explains. This precision enhances algorithms such as Kalman filters to assess stateof-charge (SoC) and state-of-health (SoH) with exceptional fidelity. The system incorporates the latest NXP dual-core lockstep microcontroller, enabling real-time error detection through cross-checking processors. “With more compute power and memory, we can run sophisticated algorithms and even handle auxiliary vehicle-control functions,” Stafl notes. The hardware stack features advanced, smart contactor drivers from Texas Instruments, ensuring robust feedback and diagnostics for electrical disconnect relays. An integrated isolation fault-monitoring system pinpoints problems within the battery stack by measuring resistance and parasitic capacitance. On the software side, Stafl introduced a partitioned architecture, separating safety-critical functions from the application layer. He says this design allows customisation without jeopardising core safety features, streamlining safety certifications and enabling flexibility for diverse applications. Additional sensors for humidity, pressure and VOC emissions enable the early detection of thermal runaway precursors, while a built-in accelerometer adds further monitoring capabilities. Stafl is now shipping BMS2000 samples, with production support slated for the second quarter of 2025. TDK introduced its IPM01, a permalloy, electromagnetic interference (EMI) shielding sheet, designed to address noise-suppression challenges in EV powertrains. The ultra-thin material, measuring just 6 µm, promises high performance while cutting weight and thickness by up to 90%, compared with conventional shielding solutions. Developed using a proprietary process in Japan, the IPM01 leverages TDK’s decades-long expertise in advanced materials. “The process is key to achieving this level of thinness and performance,” says TDK’s Bryan Burton. The material is primarily aimed at mitigating switching noise from DC-to-DC converters; a common issue in EV powertrains that can interfere with critical electronics, RF systems and cabling. E-Mobility Engineering | January/February 2025 The new BMS2000 battery management system from Stafl Systems (Image courtesy of Stafl Systems)
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