Development of Smart Battery Cells through Sensor Instrumentation and In-Vehicle Power Line Communication

Smart cells, instrumented with miniature sensors, can help meet both the consumer and regulatory demands for the battery packs of next-generation of electric vehicles (EVs). Currently, adding sensors to battery packs entails increasing vehicle weight and complexity with the associated wiring loom expansion. In this work, we demonstrate sensors for voltage, current and temperature can be installed on cylindrical cells (21700 format) and connected to a data logger via power line communication (PLC). We achieved zero error rate with our laboratory setup, and transfer times of < 40 ms (relative to dedicated wired connection). This reliable PLC method (max. data transfer rate 115 kbps) was sufficient for logging cell data and can operate over a wide DC voltage range (e.g. target 10 to 60 V typical in an EV). Our initial experiments highlight the lack of understanding of the performance of a cell during its lifetime in an EV, where temperature gradients were observed between the terminals (0.2 °C with a peak increase of +0.6 °C, discharge rate of 0.5 C).