Issue link: https://resources.mouser.com/i/1437660
26 ADI | Energy Storage Solutions Scaling Electric Vehicle Production Requires Advanced Battery Formation and Test Systems Driven by tighter CO 2 regulations and more eco- conscious consumers, the pace of migration to electric vehicles continues to accelerate. This is despite the high cost of the batteries, which stubbornly remain approximately half of the overall cost of the vehicle. While there are many factors that determine the cost of the battery, one area in which manufacturers can make significant headway in reducing cost is during the final stages of manufacturing. Specifically, during battery formation and test, which can account for up to 20 percent of the cost of an EV's battery. Battery formation and testing is a time-consuming process involving multiple charges and discharges that activate a battery's chemistry. It can take up to two full days. This necessary procedure readies the battery for use and is critical to ensure its reliability and quality. Because of how slow the process is, it is a significant bottleneck that prevents battery manufacturing from achieving greater throughput, which would lower the overall cost to produce batteries. Partnerships between EV battery manufacturers and suppliers with formation and test systems expertise are allowing them to increase their attention to reducing the time and cost involved at this crucial stage of manufacturing while still maintaining the precision required for advanced battery chemistries. Faster Throughput Equals Lower Battery Cost To decrease the cost of batteries, manufacturers need to take a holistic approach that starts by leveraging suppliers' system-level expertise to reduce the overall battery test circuit footprint while increasing the number of channels. It's important to note that both must be done while maintaining the accuracy, precision, reliability, and speed of their battery formation and test measurements to ensure safety, performance, and reliability requirements are met. This is not easy to do. For the front end, the power supplies driving the battery charging circuits need to be tightly controlled. Going deeper, battery formation and testing requires close monitoring of current and voltage profiles used during battery cycling to prevent overcharging and undercharging. This ensures safety during tests, while also maximizing battery longevity, which greatly lowers overall cost of ownership for the end user. For these critical battery measurements, very high quality instrumentation amplifiers (in-amps) and associated shunt resistors are needed to measure battery charge/discharge current to better than ±0.05% accuracy, even under harsh factory conditions. The same level of accuracy applies to the difference amplifiers used to monitor the voltage over the entire thermal operational range. Vikas Choudhary, Strategy and Marketing, Battery Testing, Analog Devices, Inc.