DCT

5:24-cv-00134

LithiumHub LLC v. Shenzhen LiTime Technology Co Ltd

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 5:24-cv-00134, E.D. Tex., 09/13/2024
  • Venue Allegations: Venue is alleged to be proper because the Defendant is a foreign corporation not resident in the United States and may therefore be sued in any judicial district.
  • Core Dispute: Plaintiff alleges that Defendant’s LiTime brand of lithium-ion batteries infringes patents related to control circuits that provide fault detection and protection.
  • Technical Context: The technology concerns solid-state switching circuits designed to manage and protect lithium-ion batteries, which are critical components in markets ranging from recreational vehicles and marine applications to off-grid power systems.
  • Key Procedural History: The inventor, Martin Koebler, is alleged to have purchased the Asserted Patents in a 2020 bankruptcy sale of his former company, StarkPower, Inc. The complaint also asserts that Defendant gained knowledge of the patents from an International Trade Commission (ITC) complaint filed by Plaintiff on September 12, 2024, one day prior to the filing of this district court action.

Case Timeline

Date Event
2010-11-29 Earliest Priority Date for '994 and '207 Patents
2016-08-09 U.S. Patent No. 9,412,994 Issued
2018-04-24 U.S. Patent No. 9,954,207 Issued
2019-01-01 StarkPower, Inc. enters bankruptcy (date stated as "2019")
2020-01-01 Inventor Martin Koebler purchases Asserted Patents
2024-09-12 Related ITC Complaint Filed against Defendant
2024-09-13 Complaint Filed

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

U.S. Patent No. 9,412,994, Lithium Starter Battery and Solid State Switch Therefor (issued Aug. 9, 2016)

The Invention Explained

  • Problem Addressed: The patent describes conventional lead-acid starter batteries as heavy, bulky, inefficient, and poor-performing in cold weather, and notes that existing electronic protection circuits can be temperamental or require manual reactivation after a fault (Compl. ¶16; ’994 Patent, col. 1:24-59).
  • The Patented Solution: The invention is a control circuit for lithium-ion batteries that uses a unique configuration of solid-state switches (e.g., MOSFETs). The design involves pairs of switches arranged in series, with their "source" or "drain" terminals connected. These pairs are then placed in parallel to handle high currents (Compl. ¶20; ’994 Patent, col. 2:36-56). This arrangement allows a controller to independently manage charging and discharging; for example, it can prevent further charging in an over-voltage condition while still allowing the battery to supply power (’994 Patent, col. 9:10-18).
  • Technical Importance: This design sought to enable the use of lighter and more powerful lithium-ion batteries as replacements for traditional lead-acid batteries in high-current applications, such as starting internal combustion engines, by providing a more robust and automated system for fault protection (’994 Patent, col. 3:20-30).

Key Claims at a Glance

  • The complaint asserts independent claims 1 and 14 (Compl. ¶28).
  • Independent Claim 1 includes:
    • A battery pack for a 12 to 120 volt operating system.
    • At least one lithium-based rechargeable cell within a housing.
    • A circuit board configured to balance each cell and provide a cutoff function.
    • The circuit board includes a "plurality of pairs of solid state switches" connected in a parallel configuration to "another pair of solid state switches."
    • Within each pair, the switches are configured such that either their "drains" or their "sources" are connected.
    • This parallel switch arrangement is connected in series with the battery cell(s).
  • The complaint reserves the right to assert additional claims (Compl. ¶30).

U.S. Patent No. 9,954,207, Lithium Battery with Solid State Switch (issued Apr. 24, 2018)

The Invention Explained

  • Problem Addressed: The ’207 Patent, a continuation-in-part of the ’994 Patent, addresses the same problems of heavy, inefficient lead-acid batteries and the need for sophisticated protection circuits for lithium-ion alternatives (’207 Patent, col. 1:30-40).
  • The Patented Solution: The patent again describes a solid-state switch architecture for protecting lithium-based cells from conditions like over-charging, over-discharging, and short circuits (’207 Patent, Abstract). The core of the solution remains the unique configuration of paired solid-state switches (e.g., MOSFETs) with interconnected "source" or "drain" terminals, allowing for independent control of current flow and providing robust fault protection (’207 Patent, col. 2:39-60). The patent explicitly notes the invention's utility as a deep cycle battery, expanding its application beyond engine starting (’207 Patent, Abstract).
  • Technical Importance: The invention provides a versatile battery protection system applicable not only to high-cranking starter batteries but also to deep cycle applications common in marine, RV, and off-grid contexts (’207 Patent, col. 5:5-9).

Key Claims at a Glance

  • The complaint asserts independent claims 1 and 12 (Compl. ¶55).
  • Independent Claim 1 includes:
    • A battery pack for powering an electric motor to start an internal combustion engine.
    • At least one lithium-based rechargeable cell within a housing.
    • A solid-state switching apparatus with a "plurality of pairs of solid state switches," where each pair is in a parallel configuration with another pair.
    • The configuration requires that within a pair, either the "drains" or "sources" of the switches are connected.
  • The complaint reserves the right to assert additional claims (Compl. ¶56).

III. The Accused Instrumentality

  • Product Identification: The accused products are lithium-ion batteries sold under the "LiTime" brand name, including a wide range of models such as the "LiTime 12V 100Ah Group 24 LiFePO4 Lithium Battery," which is identified as a representative product (Compl. ¶¶23, 26, 29).
  • Functionality and Market Context: The Accused Products are marketed as LiFePO4 deep cycle lithium batteries for applications including marine, RV, and off-grid solar systems (Compl. p. 8). A screenshot from the Defendant's website shows various LiTime battery models available for purchase. (Compl. p. 8). Defendant is alleged to sell these products in the United States through its own website and an Amazon storefront, and to maintain warehouses in Los Angeles and Dallas for distribution (Compl. ¶¶24, 25). A second screenshot depicts the Defendant's storefront on the Amazon e-commerce platform, listing various LiTime battery products. (Compl. p. 8).

IV. Analysis of Infringement Allegations

The complaint references claim charts in Exhibits D and E purporting to show infringement of the ’994 and ’207 Patents, respectively. However, these exhibits were not attached to the publicly filed complaint. The infringement theory is therefore summarized from the complaint’s narrative allegations.

  • ’994 Patent Infringement Allegations: The complaint alleges that the Accused Products, as represented by the LiTime 12V 100Ah Group 24 battery, literally infringe claims 1 and 14 (Compl. ¶¶28-29, 45). The pleading asserts that the products contain a battery housing, lithium-ion cells, and a circuit board that embodies the claimed configuration of paired solid-state switches (Compl. ¶¶30-36, 37-44). The complaint does not provide technical evidence, such as schematics or teardown photos, to substantiate how the accused batteries meet these limitations, instead incorporating the unfiled Exhibit D by reference.
  • ’207 Patent Infringement Allegations: The complaint makes parallel allegations for the ’207 Patent, asserting that the Accused Products literally infringe claims 1 and 12 (Compl. ¶¶55-56, 72). It alleges the products satisfy the elements of a battery pack with the specific solid-state switching apparatus claimed in the patent (Compl. ¶¶57-63, 64-71). As with the ’994 Patent, these allegations rely on incorporation of an unfiled exhibit (Exhibit E) and are not supported by technical evidence within the body of the complaint.
  • Identified Points of Contention:
    • Evidentiary Question: A central question will be whether Plaintiff can produce evidence that the accused LiTime batteries actually contain the specific circuit topology required by the claims. The complaint's allegations are conclusory and depend entirely on the content of the unfiled claim charts. Without teardowns, schematics, or other technical analysis, the factual basis for infringement is not established in the pleading itself.
    • Functional Question: The patents describe a specific function enabled by the claimed switch configuration: the ability to independently block charging while permitting discharging, or vice-versa (Compl. ¶20). A key issue for the court may be whether the accused products’ battery management systems perform this specific, granular control function, or if they employ a more conventional protection mechanism that disconnects the battery entirely upon a fault.

V. Key Claim Terms for Construction

  • The Term: "a plurality of pairs of solid state switches with each pair of solid state switches connected in a parallel configuration to another pair of solid state switches" (’994 Patent, cl. 1).
  • Context and Importance: This term describes the core architecture of the claimed invention. The infringement analysis will depend heavily on whether the internal circuitry of the Accused Products meets this structural definition. Practitioners may focus on this term because its specific arrangement is unconventional and its construction will likely determine the scope of the claim relative to more common battery protection circuits.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification states that solid-state switches can be placed in parallel "to increase the current capabilities" (’994 Patent, col. 9:2-3). A party might argue this supports a construction where any parallel arrangement of switch pairs designed for current handling falls within the claim's scope.
    • Evidence for a Narrower Interpretation: The patent figures, such as Fig. 16 (described as a "preferred embodiment"), illustrate a very specific topology where bidirectional switches (themselves formed from a pair of transistors) are placed in parallel with other identical bidirectional switches (’994 Patent, col. 6:40-43, Fig. 16). A party could argue that the term requires this "pair of pairs" structure, not simply any set of parallel switches, and that the phrase "connected in a parallel configuration to another pair" implies a specific relationship between distinct pairs.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges that Defendant induces infringement by intending and encouraging importers, distributors, and end users to use the Accused Products (Compl. ¶46, ¶73). The allegations are not supported by specific factual assertions, such as references to user manuals or marketing materials that instruct on an infringing use.
  • Willful Infringement: Willfulness is alleged based on Defendant’s purported knowledge of the Asserted Patents, with the complaint asserting that this knowledge arises "at least since the filing of a Complaint against them at the International Trade Commission on September 12, 2024" (Compl. ¶50, ¶77). The allegation is therefore based on knowledge acquired one day prior to the filing of the instant lawsuit.

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

  • An Evidentiary Question of Internal Structure: The case appears to hinge on a fundamental evidentiary question: what is the actual circuit design inside the accused LiTime batteries? As the complaint lacks any technical teardown or analysis, the primary task for the Plaintiff will be to prove through discovery and expert testimony that the accused products contain the specific and unconventional "plurality of pairs of solid state switches" architecture that is the cornerstone of the asserted claims.
  • A Definitional Question of Claim Scope: A dispositive legal issue will be the construction of the claim language defining the switch configuration. The court’s interpretation of whether the claims require the exact, arguably complex, topology shown in the patent’s preferred embodiments, or whether they can read on more general parallel switch designs, will be critical in determining infringement or non-infringement.