Electric Vehicle Expert Discusses Allegedly Defective Charging System

Electric Car Expert WitnessThis case in New Jersey involves an alleged product defect in a popular line of electric cars. The principal “defect” allegedly involves the charging system: customers have reported that the vehicle is not charging properly, charges too slowly, does not charge completely, and does not hold a charge as long as it should. It was believed that the root of the issue was in the vehicle’s power management software, in that the system classified routine current fluctuations in the power line to which the vehicle is plugged into to charge as potentially harmful to the onboard electrical circuits and automotive electronics in the vehicle, and automatically reducing the charging level to protect the system. As a result of the defect, some users experienced a vast decrease in the utility of their vehicle.

Question(s) For Expert Witness

  • 1. Please briefly describe your experience and familiarity with electric vehicles.
  • 2. Can you speak comfortably to potential failures in electric vehicle software? If so, could this relate to the charging system?

Expert Witness Response E-013127

I have done research on electric vehicles, and published papers on control of electric motors for electric vehicles. I have also designed and built a prototype electric vehicle that has been used for research and education purposes by multiple colleges. My primary area of expertise is nonlinear control systems, and that is what is typically used in the power electronics that control the charging and propulsion of electric vehicles. What you call “electric vehicle software” is essentially just a collection of control algorithms that are implemented in software. I am very comfortable with the intricacies of control algorithms; in fact, I already have my own working theory about this problem.

Expert Witness Response E-024232

I have been teaching graduate-level courses specifically on the design, modeling and simulation, and control developments of electric and hybrid electric vehicles for 7 years now. Based on the provided overview, I think the case would involve more than just a review of software. I would involve also what is typically called a bench testing. The bench would involve the charging system and any supporting instrumentation and accessory components. I have worked with general methodologies in designing and setting up such testing and the associated data analyses. Even though all experiences are on components other than the charging system, yet the general approach and scientific foundations are all the same. I can speak comfortably to potential failures in electric vehicle software and whether or not this could this relate to the charging system


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