MS student Raya Mahony with Advisor P. Krein
When addressing the challenges of electric vehicle (EV) charging infrastructure, it’s critical that we don’t force the solution to dwell on edge cases. Level 1 charging is more than adequate for almost all drivers almost all the time. According to the US department of Transportation, the average US driver falls just short of driving 30 miles a day. Like conventional vehicles, most modern EVs have plenty of range to allow ups and dips in daily use; so long as the vehicle is able to recover on average, most drivers will rarely need to visit an external fast charging station. Even a 90th percentile driver in a standard vehicle can bring themselves back up to their initial charge in ten hours; while that may not sound impressive, cars spend an average of 23 hours a day parked. Imagine if they were plugged in!
The battery chemistry that all electric vehicles depend on opens unique challenges and underappreciated opportunities. From a grid perspective, a connected car becomes a flexible load. If EV owners are willing to shift charging patterns to minimize cost—which to no one’s surprise, many recent studies confirm—then the grid can use these flexible loads to minimize grid strain. Effective energy pricing mechanisms can increase renewable energy use whilst decreasing dollars per mile. A higher reliance on Level 1 charging drastically minimizes costs associated with upgrading grid infrastructure. From an EV owner’s perspective, Level 1 charging is much cheaper (three times cheaper than dc fast-charging on average) and alleviates long-term battery degradation. Generously funded by the Grainger Center for Electric Machinery and Electromechanics, this research focuses on increasing the accessibility of these Level 1 charge points by addressing issues of safety, accurate charging data, payment protocols, and data security/privacy. Extending EV battery lifetime, ensuring grid stability, and charging affordability are all at stake. Figure 1 shows a PCB prototype that accesses and measures these charge points.