DCT

1:23-cv-00365

Shoals Tech Group LLC v. Voltage LLC

Log In

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:23-cv-00365, M.D.N.C., 06/28/2023
  • Venue Allegations: Venue is alleged to be proper in the Middle District of North Carolina because Defendant Voltage, LLC resides in the district, maintains physical offices with employees, is registered to do business there, and has transacted business and committed alleged acts of infringement in the district.
  • Core Dispute: Plaintiff alleges that Defendants’ solar electrical component products infringe three U.S. patents related to overmolded in-line fuse assemblies and lead assemblies that eliminate the need for traditional combiner boxes in solar panel installations.
  • Technical Context: The technology concerns Electrical Balance of System (EBOS) components, which are critical for connecting and aggregating power from solar panel arrays efficiently and durably in utility-scale solar energy projects.
  • Key Procedural History: The complaint alleges that Defendant Voltage had pre-suit knowledge of the asserted patent portfolio, citing the fact that Voltage referenced the ’254 Patent in an Information Disclosure Statement (IDS) for its own patent application. It is also alleged that Plaintiff’s counsel provided direct notice of the forthcoming ’153 Patent before its issuance.

Case Timeline

Date Event
2013-06-03 ’739 Patent Priority Date
2014-09-09 ’254 and ’153 Patents Priority Date
2020-02-04 ’739 Patent Issue Date
2021-04-27 ’254 Patent Issue Date
2022-07-21 Voltage allegedly cites ’254 Patent in its own patent application's IDS
2023-06-15 Shoals allegedly notifies Voltage of forthcoming ’153 Patent issuance and assertion
2023-06-27 ’153 Patent Issue Date
2023-06-28 First Amended Complaint Filing Date

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 10,553,739 - “Photovoltaic In Line Fuse Connector Assembly Having An Integral Fuse,” issued February 4, 2020

The Invention Explained

  • Problem Addressed: In conventional large-scale solar fields, wiring from multiple solar panel arrays is routed to a central "combiner box" which contains fuses for each array. The patent asserts that if a single panel's malfunction trips a circuit, it can shut down the entire array connected to that fuse, needlessly reducing the installation's overall efficiency (’739 Patent, col. 1:25-36).
  • The Patented Solution: The invention moves circuit protection from the centralized combiner box directly into the wiring harness itself. It describes a photovoltaic connector assembly with an integral in-line fuse. This assembly is "double molded"—first with a sealing "undermold" and then with a protective "overmold"—to create a durable, environmentally sealed unit that provides strain relief and electrical insulation (’739 Patent, Abstract; col. 2:52-54). This approach allows a fault in one panel to trip only its associated fuse, isolating the issue without affecting other panels in the array (’739 Patent, col. 2:60-63).
  • Technical Importance: By decentralizing fuse protection, the invention sought to simplify solar field architecture, reduce the quantity of expensive and cumbersome combiner boxes, and increase system uptime and energy output by improving fault isolation (Compl. ¶16; ’739 Patent, col. 2:56-63).

Key Claims at a Glance

  • The complaint asserts independent claim 1 and dependent claims 10 and 15 (Compl. ¶36).
  • Independent Claim 1 recites an in-line assembly for a solar installation, comprising:
    • A photovoltaic fuse having a solid outer surface with a first end, second end, and middle section, which defines an outline.
    • An undermold that surrounds and seals the fuse, defining an outer surface outline that is "substantially parallel" to the fuse's outline.
    • An overmold that surrounds the undermold, where the overmold and undermold are each constructed of a single unit of "dissimilar materials" and the overmold's outline is "substantially parallel" to the undermold's outline.
    • A first photovoltaic connector engaged with the fuse's first end, with the assembly providing electrical insulation.
  • The complaint does not explicitly reserve the right to assert additional dependent claims for this patent.

U.S. Patent No. 10,992,254 - “Lead Assembly For Connecting Solar Panel Arrays To Inverter,” issued April 27, 2021

The Invention Explained

  • Problem Addressed: The patent identifies that even with improved wire harnesses, conventional solar installations still require a combiner box to aggregate power from multiple solar arrays before the electricity is sent to the main inverter. These boxes are described as clumsy, prone to damage, and requiring significant installation and maintenance effort (’254 Patent, col. 1:39-50).
  • The Patented Solution: The invention is a "lead assembly," or trunk bus, that fully replaces the combiner box. It features a main "feeder cable" with one or more integrated connection "joints" where "drop lines" from solar panel arrays can connect. The electrical connection point, or "nexus," at each joint is secured (e.g., by a compression lug) and then fully encapsulated by a protective, multi-layered molding (an undermold and an overmold). This allows multiple arrays to be safely and durably connected in series along a single feeder cable that runs directly to the inverter (’254 Patent, Abstract; col. 2:1-4).
  • Technical Importance: This technology enables the complete elimination of the combiner box from a solar field's design, which can significantly reduce material costs, labor, and potential points of electrical failure, thereby simplifying the entire installation process (Compl. ¶17; '254 Patent, col. 1:49-54).

Key Claims at a Glance

  • The complaint asserts independent claims 1 and 14, and dependent claim 7 (Compl. ¶49).
  • Independent Claim 1 recites a lead assembly for a solar energy installation, comprising:
    • A first and second drop line.
    • At least one 30 amp feeder cable electrically coupled to the first drop line at a "nexus."
    • A means for securing the nexus (e.g., compression lug, soldering, splicing).
    • An undermold fully encasing the securing means, defined by a first aperture for the feeder cable and a second, smaller-diameter aperture for the drop line.
    • An overmold surrounding the undermold, forming an "undermold-overmold interface only at said outer surface," where the assembly is rated for 1500 VDC and used in an installation lacking a combiner box.
  • The complaint does not explicitly reserve the right to assert additional dependent claims for this patent.

U.S. Patent No. 11,689,153 - “Lead Assembly for Connecting Solar Panel Arrays to Inverter,” issued June 27, 2023

Technology Synopsis

  • As a continuation of the application that resulted in the ’254 patent, this patent is also directed to a lead assembly that eliminates the need for combiner boxes in solar installations (Compl. ¶18). The claims focus on the structural configuration of the molded body that encases the electrical connection ("nexus"), specifying an undermold with multiple, distinct apertures that fully encase the nexus to seal it from environmental factors (’153 Patent, Abstract; claim 1).

Asserted Claims

  • Independent claims 1, 21, and 24 (Compl. ¶59).

Accused Features

  • The Voltage LYNX Trunk Bus is accused of infringing by allegedly incorporating a lead assembly with a molded nexus joining drop lines to a feeder cable, thereby allowing for the connection of solar arrays to an inverter without a combiner box (Compl. ¶59, 63-65).

III. The Accused Instrumentality

Product Identification

  • The complaint names the "Voltage In-Line Fuse," "Voltage String Harness," and "Voltage LYNX Trunk Bus" as the Accused Products (Compl. ¶26).

Functionality and Market Context

  • The Accused Products are described as "connectors for solar panels and solar assembly products" used in utility-scale solar installations (Compl. ¶26).
    • The Voltage In-Line Fuse and Voltage String Harness are alleged to incorporate an in-line photovoltaic fuse within a molded body that includes an undermold, an overmold, and a photovoltaic connector (Compl. ¶29). An image provided in the complaint shows the components of the accused fuse assembly, including its "first end," "middle section," and "second end" (Compl. p. 10).
    • The Voltage LYNX Trunk Bus is alleged to be a lead assembly that includes drop lines, a feeder cable, an overmold, and an undermold to join separate wiring harnesses (Compl. ¶30). The complaint includes a diagram of the LYNX Trunk Bus identifying the alleged "first drop line," "feeder cable," and "nexus" (Compl. p. 10). A separate cross-section image purports to show the "overmold" and the "undermold-overmold interface at outer surface" of the LYNX Trunk Bus (Compl. p. 10).
    • The complaint alleges these products are offered as part of "wire solutions" for large solar projects and that Voltage is a "nationwide provider of utility scale wire (solar, EBOS) solutions" (Compl. ¶26).

IV. Analysis of Infringement Allegations

U.S. Patent No. 10,553,739 Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a. A photovoltaic fuse having a solid outer surface including a first end, a second end and a middle section there between, said solid outer surface defining an outline; The Voltage String Harness includes an in-line photovoltaic fuse with a first end, second end, and middle section, whose outer surface defines an outline. ¶40a col. 3:1-5
b. An undermold surrounding and sealing said fuse, said undermold defining an outer surface outline, wherein the outer surface outline of said undermold is substantially parallel relative to the outline of said solid outer surface; The fuse structure allegedly has an undermold surrounding and sealing the fuse, with an outer surface that is substantially parallel to the fuse's outline. ¶40b col. 3:13-15
c. An overmold defining an outline and surrounding said undermold, said undermold and said overmold each constructed of a single unit and each constructed of dissimilar materials, wherein the outline of said overmold is substantially parallel relative to the outline of said undermold; The fuse structure allegedly has an overmold surrounding the undermold, with the overmold and undermold being single units made of dissimilar materials, and the overmold outline is substantially parallel to the undermold's outline. ¶40c col. 4:40-45
d. A first photovoltaic connector engaged with said first end, wherein said assembly provides electrical insulation. The fuse structure includes a photovoltaic connector engaged with the fuse, and the double-molded structure provides electrical insulation. ¶40d col. 2:65-67
  • Identified Points of Contention:
    • Scope Questions: The claim requires the outline of the undermold and overmold to be "substantially parallel" to the fuse and to each other, respectively. The proper construction of "substantially parallel" will be a central issue. A court will have to determine how much geometric deviation is permissible before a structure is no longer considered parallel under this standard.
    • Technical Questions: The complaint alleges on "information and belief" that the overmold and undermold are made of "dissimilar materials" (Compl. ¶40c). A key factual question will be whether discovery confirms this material difference, as required by the claim.

U.S. Patent No. 10,992,254 Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A. A first drop line and a second drop line, said first drop line terminating in a drop line connector; The Voltage LYNX Trunk Bus is alleged to include a first and second drop line, with the first terminating in a connector. ¶53a col. 6:46-48
B. At least one 30 amp feeder cable terminating in a feeder cable connector, said first drop line and said at least one feeder cable electrically coupled at a nexus; The LYNX Trunk Bus allegedly has a feeder cable terminating in a connector that is electrically coupled to the drop line at a nexus. ¶53b col. 6:49-52
D. An undermold having an inner surface and an outer surface... said inner surface surrounding and fully encasing said securing means... comprised of a first aperture... and a second aperture... The LYNX Trunk Bus is alleged to include an undermold that fully encases the securing means and has two distinct apertures for the feeder cable and the drop line. ¶53d col. 6:57-7:3
E. An overmold surrounding said undermold and forming an undermold-overmold interface only at said outer surface, wherein said lead assembly... has a voltage rating of 1500 VDC. The LYNX Trunk Bus allegedly has an overmold that forms an interface with the undermold "only at the outer surface" and has a voltage rating of 1500 VDC. A provided cross-section visual supports this allegation (Compl. p. 10). ¶53e col. 7:4-12
  • Identified Points of Contention:
    • Scope Questions: Claim 1 recites "at least one 30 amp feeder cable." It is ambiguous whether this requires a feeder cable rated for a minimum of 30 amps or refers to a specific class of cable known as a "30 amp" cable. The construction of this term could be dispositive if the accused product uses a cable with a different rating or designation.
    • Technical Questions: The claim requires the overmold to form an interface with the undermold "only at said outer surface." While the complaint provides a visual purporting to show this feature (Compl. p. 10), the actual physical construction and manufacturing process of the LYNX Trunk Bus will be a critical factual question for the court.

V. Key Claim Terms for Construction

1. The Term: "undermold" / "overmold" (’739 and ’254 Patents)

  • Context and Importance: These terms are foundational to the patents' teachings of a durable, environmentally sealed electrical connection. The structural relationship and distinction between the two layers are recited in the independent claims of both the '739 and '254 patents. Practitioners may focus on these terms because their definition will determine the scope of protection for the core "double molding" inventive concept.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specifications describe the structures in functional terms, suggesting the terms refer to any two-layer encapsulation process. For example, the '739 patent states the "assembly is double molded to provide electrical insulation, protection and strain relief" (’739 Patent, col. 2:52-54), and the '254 patent describes an "undermold" (22) surrounded by an "overmold" (24) (’254 Patent, col. 4:50-54).
    • Evidence for a Narrower Interpretation: Both patents disclose specific preferred materials for these layers (e.g., modified polyphenylene ether for the undermold and thermoplastic elastomer for the overmold) (’739 Patent, col. 3:15-21; '254 Patent, col. 5:61-6:1). A defendant could argue that these disclosures limit the terms to embodiments using materials with similar properties or from these specific chemical families.

2. The Term: "substantially parallel" (’739 Patent)

  • Context and Importance: This term appears in claim 1 of the '739 patent to describe the geometric relationship between the fuse, undermold, and overmold. Its inherent imprecision makes it a likely candidate for dispute. Practitioners may focus on this term because even minor geometric differences in the accused product could be leveraged to argue non-infringement if a narrow definition is adopted.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patent figures, such as Figure 5, depict the components as generally concentric and following the same overall shape, which supports a reading that allows for manufacturing tolerances and slight variations in contour (’739 Patent, FIG. 5).
    • Evidence for a Narrower Interpretation: The patent does not explicitly define a degree of tolerance for "substantially." A defendant may argue that in the absence of such a definition, the term requires a high degree of conformity and that any significant deviation in shape or contour falls outside the claim's scope.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges both induced infringement under 35 U.S.C. § 271(b) and contributory infringement under § 271(c) for all three patents-in-suit. The allegations are based on Defendants allegedly encouraging, promoting, distributing, and providing instructions for the use of the Accused Products by customers and installers (e.g., Compl. ¶37-38, 50-51, 60-61).
  • Willful Infringement: The complaint alleges that Defendants' infringement has been willful. This allegation is supported by specific claims of pre-suit knowledge. For the ’739 and ’254 patents, knowledge is alleged as of at least July 21, 2022, based on Defendant Voltage’s alleged citation of the ’254 patent in an Information Disclosure Statement filed in its own patent application (Compl. ¶32). For the newly issued ’153 patent, knowledge is alleged as of June 15, 2023, based on direct notification from Plaintiff’s counsel to Defendants’ counsel (Compl. ¶33).

VII. Analyst’s Conclusion: Key Questions for the Case

  • A core issue will be one of intent and knowledge: The complaint makes specific, factual allegations of pre-suit knowledge, particularly the citation of the ’254 patent in an IDS. A key question for the court will be whether Defendants’ conduct, in light of this alleged prior knowledge, was objectively reckless, which could support a finding of willful infringement and lead to enhanced damages.
  • A second issue will be one of structural fact and evidence: The ’254 patent claims an overmold that forms an "interface only at said outer surface" of the undermold. The infringement analysis will likely turn on a key evidentiary question: does the physical construction of the accused LYNX Trunk Bus embody this precise structural limitation, or can the defense demonstrate a different method of construction that avoids it?
  • Finally, the case may turn on a question of definitional scope: The ’739 patent uses the term "substantially parallel" to define its claimed geometry. The resolution of the infringement claim for that patent will depend on how broadly or narrowly the court construes this ambiguous term, and whether the accused products fall within that definition.