After four years of litigation, Australian-based CAP-XX, Ltd. finally commenced its patent infringement trial this Monday against Maxwell Technologies, Inc. before Judge Jennifer Hall and a Delaware jury and is set to end on Friday. According to the Court’s docket, jury selection and instructions were completed, and trial presentations began, on Monday. Judge Hall also issued an order the day before on Sunday declining Maxwell’s request to construe certain claim terms that came into dispute based on Maxwell’s summary judgment motion for invalidity. Before trial, Judge Connolly had denied each of Maxwell’s three summary judgment motions invalidity (arguing improper enablement and written description) and non-infringement (arguing time barred damages, improper marking, and no indirect infringement).

CAP-XX filed its complaint against Maxwell on September 16, 2019, alleging willful direct and indirect infringement of U.S. Patent Nos. 6,920,034 (“the ’034 Patent”) and 7,382,600 (“the ’600 Patent”) by numerous Maxwell capacitor products, including certain ultracapacitor cells for hybrid vehicle applications—just months after Tesla acquired Maxwell in May 2019 for $218 million.

In a somewhat unexpected twist, and despite divesting itself of Maxwell’s ultracapacitor business in July 2021 to a San Diego-based startup called UCAP Power, Tesla sued CAP-XX earlier this year in July 2023 in the Eastern District of Texas, alleging that the Australian company is willfully infringing U.S. Patent Nos. 8,279,580 and 8,591,601 directed to “electrode[s] for energy storage device” and methods for making “active electrode material” through dry electrode methods. Interestingly, in its complaint, Tesla alleges that “CAP-XX previously filed suit against [Maxwell and that] Maxwell has a history of innovation that has resulted in its own patents, now assigned to Tesla, and thus Tesla brings this suit against CAP-XX to protect its intellectual property rights.” The case is styled as Tesla v. CAP-XX, No. 2-23-cv-00334 (E.D. Tex. 2023) and has been assigned to Judge Gilstrap.

The Delaware case is styled as CAP-XX v. Maxwell, No. 1-19-cv-01733 (D. Del. 2019) and we’ll be reporting on the trial as it plays out this week and next.