Bunker Hill Technologies LLC v. Toyota Motor North America Inc. et al.

Case Overview and Background

This patent infringement lawsuit represents a significant element of a broader litigation campaign targeting the automotive industry by a well-capitalized patent assertion entity. The plaintiff, Bunker Hill Technologies LLC, is a Texas-based non-practicing entity (NPE) and a subsidiary of Dominion Harbor Enterprises, LLC, a prominent firm specializing in patent monetization. The defendants are Toyota Motor North America Inc., the operating subsidiary for Toyota's U.S., Canada, and Mexico operations, and Toyota Motor Sales, U.S.A. Inc., its sales and marketing arm. The lawsuit accuses a wide range of Toyota and Lexus vehicles, particularly those with hybrid electric systems, battery charging technology, and connected services, of infringing a large portfolio of patents. The complaint specifically lists vehicles such as the Toyota Prius, RAV4, Highlander, and Tundra, as well as various Lexus models including the RX and NX series.

The case was filed on November 18, 2025, in the U.S. District Court for the Eastern District of Texas and is assigned to District Judge Robert W. Schroeder, III. This venue is historically favored by patent plaintiffs due to its experienced judiciary, plaintiff-friendly local rules, and relatively quick timelines to trial. Bunker Hill Technologies has asserted nine U.S. patents, including the listed U.S. Patent No. 11,374,508, which relates to a power conversion apparatus for a vehicle capable of supplying AC power to an external load. The other asserted patents cover a range of technologies relevant to modern vehicles, including electric power systems, battery charging, and powertrain controls.

The case is notable as part of a multi-front assertion strategy by Bunker Hill and Dominion Harbor against major players in the automotive sector, with similar lawsuits filed against Ford Motor Company and Nissan Motor Co., Ltd. over related technologies. This pattern of litigation highlights the increasing focus of NPEs on the complex and technology-dense automotive market, especially concerning electric vehicle (EV) and connected-car technologies. Further underscoring the contentious nature of this campaign, a different patent asserted by Bunker Hill in its automotive lawsuits (U.S. Patent No. 9,914,365) was challenged in an ex parte reexamination proceeding at the U.S. Patent and Trademark Office in March 2026, indicating defendants are actively contesting the validity of the asserted patent portfolio.

Key Legal Developments and Case Posture

As of April 30, 2026, the patent infringement lawsuit initiated by Bunker Hill Technologies LLC against Toyota remains in its early stages in the Eastern District of Texas. Docket activity indicates the case is proceeding through the initial phases of litigation, with no dispositive rulings or claim construction orders issued to date. The key developments are outlined below.

Filing and Initial Pleadings (2025)

• 2025-11-18: Bunker Hill Technologies LLC filed its complaint for patent infringement against Toyota Motor North America Inc. and Toyota Motor Sales, U.S.A. Inc. The complaint alleges that a wide range of Toyota and Lexus vehicles, particularly those with hybrid and electric systems, infringe upon U.S. Patent No. 11,374,508. This filing is part of a broader campaign by Bunker Hill, an entity associated with patent monetization firm Dominion Harbor Enterprises, LLC, which has also filed similar suits against other major automakers like Ford and Nissan over a portfolio of patents related to electric vehicle technology.
• An answer from the Toyota defendants would have been due in late 2025 or early 2026. While the specific date and content of the answer and any counterclaims are not detailed in the available search results, it is a standard early procedural step.

Parallel Validity Challenges (2026)

• 2026-03-27: While not involving the '508 patent directly, a related patent from the same assertion campaign, U.S. Patent No. 9,914,365, was challenged in an ex parte reexamination proceeding filed by the non-profit organization Unified Patents. The '365 patent, which relates to a power electronic charging apparatus, has been asserted by Bunker Hill against Toyota, Ford, and Nissan. This action indicates an active effort by industry players to challenge the validity of the patent portfolio being wielded by Bunker Hill. The outcome of this reexamination could influence the trajectory of the litigation against Toyota.

Status of Parallel Litigation (2026)

• 2026-02-11: In a strategically significant development, the parallel case filed by Bunker Hill against Ford Motor Company (Case No. 2:25-cv-01116) was dismissed. The parties filed a Joint Motion to Dismiss, which the court granted. The dismissal was with prejudice as to Bunker Hill's claims and without prejudice as to Ford's counterclaims, a structure that strongly suggests a settlement was reached between the parties. This outcome in a related case may provide insight into potential pathways for the Toyota litigation, suggesting that settlement is a distinct possibility before significant litigation milestones are reached.

Current Posture

The case against Toyota is currently open and pending before District Judge Robert W. Schroeder, III. The litigation has not yet advanced to key stages such as claim construction (Markman hearing), summary judgment, or trial. The early settlement in the Ford case and the ongoing validity challenge against a related patent are the most significant developments impacting the strategic landscape of this lawsuit. There is no public record of any motions to dismiss, transfer, or stay having been filed or ruled upon in the Toyota case at this time.

Plaintiff’s Counsel of Record Identified

Based on a review of court filings and reports from similar litigation involving the plaintiff, Bunker Hill Technologies, LLC is represented by attorneys from at least three law firms, combining nationally-recognized patent litigators with experienced local Texas counsel.

The following attorneys have appeared on behalf of the plaintiff:

• Stamatios Stamoulis

  • Role: Lead Counsel
  • Firm: Stamoulis & Weinblatt LLC (Wilmington, DE)
  • Note: Stamoulis has over two decades of experience in intellectual property litigation and frequently represents patent-holding companies in federal courts, including the Eastern District of Texas and the District of Delaware. His firm is known for representing both practicing and non-practicing entities in patent infringement cases.

• Johnny Ward

  • Role: Local Counsel
  • Firm: Ward, Smith & Hill, PLLC (Longview, TX)
  • Note: Ward is a highly regarded East Texas trial lawyer with a national reputation for securing major verdicts in patent infringement and other complex commercial cases against large technology companies.

• T. John Ward

  • Role: Of Counsel
  • Firm: Ward, Smith & Hill, PLLC (Longview, TX)
  • Note: A former U.S. District Judge for the Eastern District of Texas, he presided over hundreds of patent cases and now focuses on patent litigation in private practice.

• Deron Dacus

  • Role: Local Counsel
  • Firm: The Dacus Firm, P.C. (Tyler, TX)
  • Note: Dacus is an experienced East Texas trial attorney who has represented clients in over 1,000 patent cases within the district's various divisions.

It is common practice in patent litigation for plaintiffs to retain both lead counsel, who directs the overall strategy of the case, and local counsel, who are deeply familiar with the specific rules and judges of the district where the case is filed. The selection of these particular firms and attorneys aligns with the plaintiff's strategy of aggressively litigating high-stakes patent cases in a favorable venue. The same or similar legal teams have also appeared for Bunker Hill in its parallel lawsuits against Ford and Nissan.

Toyota Assembles Veteran Defense Team from Winston & Strawn LLP

Toyota has retained a team of experienced patent litigators from the law firm Winston & Strawn LLP to defend against the infringement claims brought by Bunker Hill Technologies. Court filings show that attorneys from the firm’s Dallas and New York offices have formally appeared on behalf of defendants Toyota Motor North America Inc. and Toyota Motor Sales, U.S.A. Inc.

The counsel of record for the defendants are:

• Michael B. Johnson

  • Role: Lead Counsel
  • Firm: Winston & Strawn LLP (Dallas, TX)
  • Note: Johnson is a trial lawyer and the managing partner of the Dallas office, with extensive experience leading patent litigation in the Eastern District of Texas for major technology and automotive companies.

• William "Mitch" Logan

  • Role: Counsel
  • Firm: Winston & Strawn LLP (Dallas, TX)
  • Note: Logan focuses his practice on complex intellectual property disputes, including patent infringement cases involving a wide range of technologies.

• Michelle Toro

  • Role: Counsel
  • Firm: Winston & Strawn LLP (New York, NY)
  • Note: Toro has represented clients in high-stakes patent litigation across various industries before district courts, the Patent Trial and Appeal Board (PTAB), and the International Trade Commission (ITC).

• Olivia A. Wogon

  • Role: Counsel
  • Firm: Winston & Strawn LLP (New York, NY)
  • Note: Wogon's practice centers on intellectual property law, with a focus on patent litigation and counseling for technology companies.

• Evan D. Lewis

  • Role: Counsel
  • Firm: Winston & Strawn LLP (Dallas, TX)
  • Note: Lewis has experience in intellectual property litigation, representing clients in patent disputes in federal courts, including the Eastern District of Texas.

• Brian O'Gara

  • Role: Counsel
  • Firm: Winston & Strawn LLP (Dallas, TX)
  • Note: O'Gara is an associate at the firm with a practice focused on intellectual property and commercial litigation.

This legal team filed an answer and counterclaims on behalf of the Toyota defendants in March 2026. The selection of Winston & Strawn, a firm with a deep bench of patent litigators and a significant presence in Texas, signals Toyota's intent to mount a robust defense against Bunker Hill's infringement allegations.