E-Mobility Engineering 014 l InoBat Auto dossier l In Conversation: Brandon Fisher l Battery monitoring focus l Supercapacitor applications insight l Green-G ecarry digest l Lithium-sulphur batteries insight l Cell-to-pack batteries focus

began working as a project design engineer for Cooper-Bussman, with a similar focus to where he had left off at MillenWorks – on electrical engineering work for vehicles. “I joined them in 2010, and soon found myself specialising in their power distribution systems. Then, in 2011, they were acquired by Eaton,” he says. “Soon after their product manager for power distribution left, as the leading engineer in that department I stepped into the role to start handling some of the business side of things for Eaton’s power systems product line. It also allowed me to start coordinating some of the strategy of how the line was going to develop based on where customers – that is, vehicle manufacturers – were taking their designs.” Over the following few years, Eaton gradually began changing its power distribution technologies from copper and plastic wiring-based systems to printed circuit boards, in essence going from classic bulky fuse boxes to slimmer, smart fuse boxes with microcontrollers running CAN buses and exporting diagnostic data before and after a fuse had blown or other incidents occurring. “It was also when we began looking at HV power distribution opportunities,” Fisher says. “Some of the projects we have now were envisioned back then, in a ‘hybrid group’ within Eaton that had previously launched an electric hybrid drive unit by procuring parts and working as the systems integrator. “We’d sold that platform to some big customers, including Daimler and Navistar. I looked at its powertrain from a power distribution perspective and saw some opportunities there. “For instance, there was a project with the US Department of Energy at the time called Supertruck, where they were trying to drastically reduce the emissions and boost the efficiency of older freight vehicles. After talking with potential customers there we started giving technology demonstrations and prototyping HV distribution systems for them.” Safety at high voltage By this time, the consensus had grown within Eaton that HV powertrain technologies were going to become a critical area of business. Less clear was when it would happen, and hence when would be the right time to ramp up investment in e-mobility. It was around 2014, soon after Fisher started moving back from business-related decision-making into engineering team leadership, that Caterpillar – one of Eaton’s key customers – formulated a strategy to electrify all 135 of its platforms. “At the time, we were working on their second HV inverter solution for an electrified paver – both the main powertrain inverter and an auxiliary inverter for powering lights, coffee machines and so on for night-time jobs,” he says. “That was really our first production e-mobility solution. And things really took off soon after, in a side project [still at Eaton] where our team was evaluating HV power distribution for passenger cars, both as internal r&d and also for some companies. Some Ford engineers for instance sent us a specification for some HV vehicle systems to find out what we could make in line with them. “That drove us to start prototyping HV fuse boxes, starting with industrial fuses that traditionally didn’t get more than five thermal cycles in a day, but when you put those on an EV, a single acceleration and deceleration counts as one cycle. Fisher has spearheaded the development of the Breaktor, an HV circuit-breaker developed to replace traditional automotive contactor-and-fuse junctions in EVs 18 Summer 2022 | E-Mobility Engineering