19 one cell per second. Each of the commercial vehicle-bound cells weighs approximately 2.2 kg, and Persson comments that the ergonomics of handling such large cells requires an automated setup. “We’ve made sure to install a copious plethora of sensors to ensure we’re always measuring the state of our assembly equipment, of the processes, and of the products, all along the production line,” he says. “And one of the first steps in our facility involves testing all of the battery cells for parameters like performance over temperature, voltage and internal resistance, and we then compare our results in a database with results provided by Northvolt from their own testing processes. “But really, for me the biggest advantage of having sensors and measurement all over every part of the facility is being able to visualise any step in the production process at any given moment. We routinely set up visualisation layers to suit each operator at every machine on the shop floor, to aid them in monitoring the speed, consistency or health of each process, so they can instantly know how efficiently or safely each tool is operating in real-time.” On a larger scale, workshop or factory managers use all this data to visualise how well the facility is running, gauging values such as quality yields and machine uptimes, and pinpointing potential bottlenecks where some efficiency might be gained via reworks of or countermeasures within the production line. Persson additionally notes, “The assembly machines collect data on things like the torque curves of their implements. If machine learning-based AI can autonomously identify where one such curve is starting to shift, then it can trigger either a notification to maintenance teams for inspection or replacement, or even just a software correction by the machine to return its torque curve to normal. AI offers huge potential for maintenance teams to identify or predict risks of future degradation or equipment. “And I think we’ll be discovering more and better forms of welding in the near future; welding plays a huge part in the production of batteries, but each type of welding process comes with so many risks, so many things that need constant checking and control to prevent issues like forming errors or contaminations. If we speak again within two years, I wouldn’t be surprised to tell you that we’ve switched from laser welding to wire bonding or something like that.” Scania in operation The standard pack coming off this assembly line is presently a 700 V nominal unit storing 100 kWh of energy, though a bigger pack is also manufactured which modularly combines 200 kWh worth of modules, and also integrates two control units for added safety and redundancy. “The bigger packs are a critical enabler for the longer-distance transport EVs, and fortuitously we expect those systems to be very well ranged for moving people or materials between Northvolt’s facility and ours, as well as for the busy routes between Stockholm and its surrounding towns, or between the west and east coasts of Sweden with a single charging stop somewhere in the middle,” Persson notes. “I’ve also conversed about those packs with peers in Germany, and there’s for instance a route in Southern Bavaria, where one of the sports car manufacturers runs trucks for transporting huge pallets of cars from the factory to dealerships. It’s around a three hour loop for that truck to leave and return to the production centre, which is a perfect fit for the sort of 600 kWh EV we’re developing now; and as our facility produces batteries entirely using wind and hydro power, the only step that remains is instructing national and local governments on the need for better vehicle charging and electrical infrastructure to bring about zero-pollution mobility.” The future Persson says, “we’ve found our initial standard battery pack is a good fit for the mining industry, and for heavy construction vehicles. Leveraging new technologies will also be important and battery technologies will certainly evolve to enable trucks and buses to fast-charge in 30 minutes or less while maintaining long life expectancy. The next few years are going to be exciting.” E-Mobility Engineering | January/February 2024 Tony Persson Tony Persson studied a Masters in Engineering at Lulea University of Technology in the north of Sweden from 1994 to 2000. That education included a one year stint as a blue-collar worker at a Saab Automobile press shop from 1996 to 1997. He additionally achieved an MSc Eng in Manufacturing and Process Engineering from the University of South Australia in a placement that ran from 1999 to 2000. Following his graduation, he entered Scania and spent 14 years and 7 months working across a variety of positions, including engineer, project manager, and production manager, across different aspects of the Swedish company’s technical activities including chassis production, material handling and supplier quality assurance. He and his family moved to Kuala Lumpur, Malaysia for three years, then lived in Germany for around three further years before returning to Sweden to rejoin Scania as head of battery production. Outside of his career in e-mobility, Persson is also an Ironman-certified fitness coach, and to date still consults on matters of personal fitness and triathlon training, as well as management and business development.
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