Voltage LLC v. Shoals Technologies Group LLC

1. Case Identification

• Case #: IPR2025-01443
• Patent #: 12,015,375
• Filed: August 19, 2025
• Petitioner(s): Voltage, LLC; Ningbo Voltage Smart Production Co.
• Patent Owner(s): Shoals Technologies Group, LLC
• Challenged Claims: 1-2, 4-8, 10-17, and 19-24

2. Patent Overview

• Title: Lead Assembly for Solar Panel Arrays
• Brief Description: The ’375 patent discloses lead assemblies for connecting solar panel arrays directly to an inverter, bypassing the need for a traditional combiner box. The invention centers on a joint where one or more "drop lines" are electrically coupled to a "feeder cable" at a connection "nexus," with the entire joint encapsulated by a monolithic, overmolded structure.

3. Grounds for Unpatentability

Ground 1: Obviousness over Machida - Claims 1-2, 4-8, 10-17, and 19 are obvious over Machida.

• Prior Art Relied Upon: Machida (Japanese Application Publication No. JPH10-135499A).
• Core Argument for this Ground: Petitioner asserted that Machida, a reference not cited during prosecution, discloses nearly every limitation of the challenged single-drop-line claims and renders the remaining claims obvious.
  • Prior Art Mapping: Petitioner argued that Machida’s T-shaped connector for wiring solar cell modules is the claimed “lead assembly.” This connector joins a vertical electrical wire (the “drop line”) to a horizontal base wire (the “feeder cable”) at a connection point (the “nexus”) where exposed portions of the wires are soldered together. The entire joint is encapsulated by an injection-molded outer shell (the “monolithic mold”) which provides distinct pathways for the wires to enter and exit. For claims requiring two or more drop lines (e.g., claim 6), Petitioner contended that modifying Machida’s connector to accept a second drop line would have been a simple, obvious design choice.
  • Motivation to Combine (for modification): A POSITA would be motivated to modify Machida’s single-drop-line connector to include additional drop lines to further Machida’s own stated goal of making wiring work “less time-consuming and safer.” Using a single, multi-drop line connector reduces the total number of connections required to wire a solar array, increasing installation efficiency.
  • Expectation of Success (for modification): A POSITA would have a high expectation of success in making such a modification, as it involves a predictable alteration to a known connector design to achieve a known benefit.

Ground 2: Obviousness over Machida in view of Solon - Claims 6, 15-17, 19-20, and 22-24 are obvious over Machida in view of Solon.

• Prior Art Relied Upon: Machida (Japanese Application Publication No. JPH10-135499A) and Solon (Application # 2011/0011642).
• Core Argument for this Ground: For claims requiring two or more drop lines, Solon explicitly teaches the multi-drop line configurations that Petitioner argued would be an obvious modification to Machida’s foundational connector design.
  • Prior Art Mapping: Machida was asserted to teach the core structure: an overmolded connector joining a drop line to a feeder cable. Solon was asserted to supply the missing element for multi-drop line claims by disclosing low-leakage wire harnesses for solar utilities that expressly feature T-joints and cross-joints. These joints show multiple branch wires (drop lines) connecting to a single trunk wire (feeder cable).
  • Motivation to Combine: A POSITA would combine the references to improve the efficiency of the system disclosed in Machida. Solon’s teaching of multi-branch connections provides a clear path to connecting more solar panels with fewer components, which directly aligns with Machida’s objective of simplifying and accelerating solar field wiring. Both references are analogous art from the specific field of solar power connectors.
  • Expectation of Success: A POSITA would have a reasonable expectation of success because the combination involves applying Solon's known and simple multi-branch joint configuration to Machida's basic connector, representing a straightforward integration of compatible technologies for a predictable improvement.

Ground 3: Obviousness over Machida in view of Kim - Claims 6, 15-17, and 19-24 are obvious over Machida in view of Kim.

• Prior Art Relied Upon: Machida (Japanese Application Publication No. JPH10-135499A) and Kim (Korean Patent No. 10-1428689).
• Core Argument for this Ground: Kim serves as an alternative to Solon, providing strong evidence that multi-drop line connectors were a well-known and obvious design choice for solar power applications.
  • Prior Art Mapping: As in the other grounds, Machida was presented as teaching the fundamental molded connector. Kim was asserted to teach a cable connection device for photovoltaic modules that explicitly couples cables in X-shape, Y-shape, or T-shape arrangements. Kim’s figures illustrate two drop line cables branching from a central feeder cable within a single sealed joint, directly teaching a dual drop line configuration.
  • Motivation to Combine: A POSITA would be motivated to modify Machida’s T-shaped connector to an X-shape based on Kim's teachings to connect additional solar panels to one connector, thereby increasing installation efficiency and reducing component count. Kim's focus on sealing the connection against harsh outdoor environments complements Machida's disclosure of a waterproof plug.
  • Expectation of Success: The combination would yield predictable results. It entails modifying Machida’s connector using a well-understood form factor (a cross-shape) taught by Kim for the identical purpose of joining multiple solar cables in the same technical field.

4. Key Claim Construction Positions

• Petitioner proposed that the Board adopt the claim constructions from a Claim Construction Order issued in parallel ITC litigation (Inv. No. 337-TA-1438). Key proposed constructions included:
  • "lead assembly": "an assembly for electrically coupling a solar panel array" or "a plurality of solar panel arrays," with a deferred construction on whether the term excludes a combiner box.
  • "nexus": "region in which a drop line and a feeder cable are electrically coupled."
  • "opposite direction(s)": The plain and ordinary meaning, which "does not require precisely 180 degrees of separation."
• Petitioner argued these constructions were appropriate for the IPR but also maintained that the challenged claims are invalid under a plain and ordinary meaning standard if no explicit construction is adopted.

5. Relief Requested

• Petitioner requested the institution of an inter partes review and the cancellation of claims 1-2, 4-8, 10-17, and 19-24 of the ’375 patent as unpatentable under 35 U.S.C. §103.