First wireless battery management system showcased at electronica

This wireless BMS concept car, developed by Linear’s design partner LION Smart, combines Linear’s highly accurate battery stack monitors with its SmartMesh wireless mesh networking products in a BMW i3, replacing the traditional wired connections between the battery packs and the battery management system. This demonstration of a fully wireless BMS car represents a significant breakthrough that offers the potential for improved reliability, lower cost and weight, and reduced wiring complexity for large multicell battery stacks for electric and hybrid/electric vehicles.

Automakers are challenged to ensure the driving public that electric and hybrid/electric vehicles are both safe and reliable. Linear’s road-proven high voltage battery stack monitors deliver industry leading accuracy and reliability, enabling battery management systems that maximize battery pack performance and longevity. The LTC6811 is a complete battery measuring device for hybrid/electric vehicles that can measure up to 12 series-connected battery cell voltages with better than 0.04% accuracy. Combining the LTC6811 with Linear’s SmartMesh wireless mesh networking system addresses the persistent reliability issues associated with automotive wiring harnesses and connectors.

Field-proven in IIoT applications, SmartMesh embedded wireless networks deliver >99.999% reliable connectivity in harsh environments by employing path and frequency diversity. In addition to improving reliability by creating multiple points of redundant connectivity, the wireless mesh network enables additional BMS capability. Wireless connectivity enables more flexible placement of battery modules, and makes possible the installation of sensors in locations previously unsuitable for a wiring harness. Wireless sensors integrated into the SmartMesh network, such as current and temperature monitors, offer the potential for synchronising these measurements with cell voltages.

Erik Soule, Vice President, Signal Conditioning Products for Linear Technology, stated: “Linear’s innovations in two critical industry leading technologies enables wireless battery management at automotive reliability levels. New designs of electric and hybrid/electric vehicles are increasing rapidly and all of the major automotive manufacturers are searching for ways to improve the performance and reliability of their battery management systems as they move into higher volume production. The wireless BMS concept car, realised through the expertise of LION Smart’s BMS design, showcases our product vision.”

Mr. Daniel Quinger, CEO of LION Smart, stated: “One of our goals in this ambitious project is to demonstrate the improvement in range and charging time that can be achieved by using the latest technologies in partnership with leading global players. Combining Kreisel Electric’s laser welded 18650 modules with direct liquid cooling and Linear Technology’s SmartMesh IP wireless mesh and the LTC6811 battery monitoring IC, together with LION Smart’s Open BMS, enabled a unique battery system with record breaking charge time of just 15 minutes, an energy capacity of over 55kWh, with a range of over 400km. This represents a truly remarkable accomplishment.”

The wireless BMS concept car, featuring the BMW i3, shows the promise of wireless technology to significantly improve reliability and simplify the design of automotive battery management systems.