Champion Power Equipment Inc. v. Generac Power Systems Inc.

Champion Power Equipment Inc. (Champion) has initiated a patent infringement lawsuit against Generac Power Systems Inc. (Generac), both prominent operating companies in the power generation equipment industry. Champion, established in Santa Fe Springs, California in 2003, manufactures a wide range of power products including portable generators, home standby generators, inverters, and engines. Generac, headquartered in Waukesha, Wisconsin, is a long-standing American manufacturer (founded 1959) of backup power generation products for residential, light commercial, and industrial markets, offering various generators, transfer switches, and energy management solutions.

The litigation, filed on October 9, 2024, in the U.S. District Court for the Eastern District of Wisconsin (Case No. 2:24-cv-01281), accuses five models of Generac's portable generators, some sold under the "Powermate" brand, of infringing eleven of Champion's patents. These accused products are described as dual-fuel or multi-fuel generators, capable of operating on either propane or gasoline. The asserted patents, including U.S. Patent No. 10,598,101, generally relate to multi-fuel generators or specific features thereof. U.S. Patent No. 10,598,101, for example, describes a multi-fuel engine system that can run on a gaseous fuel or a liquid fuel. The case is currently in the motion practice stage before Judge Lynn Adelman. The Eastern District of Wisconsin is Generac's home venue, a common and permissible choice for patent litigation under 28 U.S.C. § 1400(b) when a defendant has a regular and established place of business there.

This case is notable as it represents a direct competitor dispute within the significant portable generator market. Generac has not only filed counterclaims of non-infringement and invalidity against Champion's asserted patents but has also brought its own counterclaims alleging infringement by Champion of two Generac patents related to carbon monoxide detection. Furthermore, the dispute extends to the Patent Trial and Appeal Board (PTAB), where Generac has filed inter partes review (IPR) petitions challenging Champion's patents. In a significant development, the PTAB Director vacated institution decisions in two related IPRs (IPR2025-00805 & IPR2025-00951), finding that Generac advanced inconsistent claim construction positions between the district court litigation and the IPR proceedings, which is disfavored under recent PTAB guidance. This ongoing multi-forum battle highlights the strategic complexities and high stakes involved in patent enforcement and validity challenges between key industry players.

Key Legal Developments and Outcome for Champion Power Equipment Inc. v. Generac Power Systems Inc. (2:24-cv-01281)

This patent infringement litigation, filed in the U.S. District Court for the Eastern District of Wisconsin, is ongoing. The case involves allegations by Champion Power Equipment Inc. (Champion) that Generac Power Systems Inc. (Generac) infringes eleven of Champion's patents, including U.S. Patent No. 10,598,101, with five models of Generac's portable generators. Generac has asserted counterclaims of non-infringement and invalidity.

Chronological Summary of Developments:

• 2024-10-09: Case Filing
  Champion Power Equipment Inc. filed the patent infringement lawsuit against Generac Power Systems Inc. in the U.S. District Court for the Eastern District of Wisconsin.
• 2024-10-29: Stipulation for Protective Order Filed
  The parties filed a stipulation for the entry of a protective order.
• 2024-11-04: Protective Order Issued
  The Court issued the parties' stipulated protective order.
• 2025-01-22: Generac's Motion to Dismiss Denied
  Generac filed a motion to dismiss Champion's complaint for failure to state a claim, arguing that the complaint lacked sufficient factual allegations linking the physical features of its generators to the asserted claims. The court denied this motion, finding it plausible that the accused dual-fuel generators could satisfy all elements of the claims identified in the complaint.
• 2025-09-18: Parallel IPR Proceedings Initiated and Counsel Changes
  Multiple Inter Partes Review (IPR) proceedings were initiated at the Patent Trial and Appeal Board (PTAB) by Generac and other entities against Champion's patents:
  • IPR2025-00805: Initiated by Harbor Freight Tools USA Inc., Generac Power Systems, Inc., and MWE Investments, LLC, challenging U.S. Patent No. 10,393,034. This IPR's documents reference the district court case 2:24-cv-01281.
  • IPR2025-00951: Initiated by Generac Power Systems, Inc. as Petitioner against Champion Power Equipment, Inc. as Patent Owner, specifically challenging U.S. Patent No. 10,598,101. An order conditionally granting the Patent Owner's motion for withdrawal and substitution of counsel was issued on this date for both IPR2025-00805 and IPR2025-00951.
• 2025-09-26: Generac's Invalidity Contentions Deadline Extended
  Generac's deadline to file its Invalidity and Unenforceability Contentions was extended to September 26, 2025, following an expedited non-dispositive motion to amend a scheduling conference order.
• After 2026-09-11: Markman Hearing Scheduled
  The Markman (claim construction) hearing is scheduled to occur after September 11, 2026. Other discovery milestones, such as initial expert witness disclosures and fact discovery cutoff, are tied to the date of the court's claim construction order.

Current Posture:

The case is in the pre-trial stage, with claim construction briefing and hearing still pending. No trial events, verdict, or final disposition have occurred, and no settlement or appeal has been reported. Parallel PTAB proceedings are active, with IPR2025-00951 directly challenging U.S. Patent No. 10,598,101, one of the key patents in this litigation. The outcome of these IPRs could significantly impact the district court case.

Plaintiff Champion Power Equipment Inc. is represented by the following counsel:

• Jacob M. Fritz (Counsel)

  • Firm: Ziolkowski Patent Solutions Group SC, Port Washington, WI
  • Note: Co-founded Ziolkowski Patent Solutions Group SC, focusing on patent litigation.

• Timothy J. Ziolkowski (Counsel)

  • Firm: Ziolkowski Patent Solutions Group SC, Port Washington, WI
  • Note: Co-founded Ziolkowski Patent Solutions Group SC and has experience in patent prosecution and litigation.

• Thomas P. Heneghan (Counsel)

  • Firm: Husch Blackwell LLP, Madison, WI
  • Note: A partner at Husch Blackwell LLP with experience in intellectual property litigation.

• Jennifer Elizabeth Hoekel (Counsel)

  • Firm: Husch Blackwell LLP, St. Louis, MO
  • Note: A partner at Husch Blackwell LLP focusing on intellectual property, including patent litigation.

• Avery Hitchcock (Counsel)

  • Firm: Husch Blackwell LLP, Milwaukee, WI
  • Note: Counsel at Husch Blackwell LLP, listed as representing the plaintiff in this case.

• Sharif Ahmed (Counsel)

  • Firm: Husch Blackwell LLP, Phoenix, AZ
  • Note: Counsel at Husch Blackwell LLP, with experience in intellectual property disputes.

• Kimberly Gutierrez (Counsel)

  • Firm: Husch Blackwell LLP, St. Louis, MO
  • Note: Attorney at Husch Blackwell LLP, listed as counsel for the plaintiff.

Generac Power Systems Inc. is represented by counsel from two law firms: Merchant & Gould PC and Reinhart Boerner Van Deuren SC.

The following attorneys are listed as counsel of record for Generac:

Merchant & Gould PC

• Joseph Dubis
  • Role: Likely lead counsel (firm is based outside the forum state).
  • Firm: Merchant & Gould PC, Minneapolis, MN.
  • Experience Note: Dubis is an intellectual property attorney with experience in patent litigation.
• Michael A. Erbele
  • Role: Likely lead counsel.
  • Firm: Merchant & Gould PC, Minneapolis, MN.
  • Experience Note: Erbele is listed as counsel for Generac in this patent infringement case.
• Thomas J. Leach
  • Role: Likely lead counsel.
  • Firm: Merchant & Gould PC, Minneapolis, MN.
  • Experience Note: Leach has appeared on behalf of Generac in this and other related matters, including a motion to dismiss.
• Gabrielle Kiefer
  • Role: Likely lead counsel.
  • Firm: Merchant & Gould PC, Minneapolis, MN.
  • Experience Note: Kiefer is listed as counsel for Generac in this patent infringement case and has appeared in docket entries.
• Elisabeth S. Muirhead
  • Role: Likely lead counsel.
  • Firm: Merchant & Gould PC, Minneapolis, MN.
  • Experience Note: Muirhead is listed as counsel for Generac in this patent infringement case.
• Paige S. Stradley
  • Role: Likely lead counsel.
  • Firm: Merchant & Gould PC, Minneapolis, MN.
  • Experience Note: Stradley is listed as counsel for Generac in this patent infringement case.

Reinhart Boerner Van Deuren SC

• Monica A. Mark
  • Role: Local counsel (firm is based in the forum state).
  • Firm: Reinhart Boerner Van Deuren SC, Madison, WI.
  • Experience Note: Mark has appeared on behalf of Generac and is listed as counsel for the defendant.
• Paul J. Stockhausen
  • Role: Local counsel.
  • Firm: Reinhart Boerner Van Deuren SC, Milwaukee, WI.
  • Experience Note: Stockhausen has appeared on behalf of Generac and is listed as counsel for the defendant.