DCT

2:22-cv-00401

RJ Technology LLC v. Samsung Electronics Co Ltd

Log In

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:22-cv-00401, E.D. Tex., 10/13/2022
  • Venue Allegations: Plaintiff alleges venue is proper in the Eastern District of Texas because Defendant Samsung Electronics America, Inc. maintains regular and established places of business in the district, including corporate offices in Plano and a retail store in Frisco, and has committed acts of infringement in the district.
  • Core Dispute: Plaintiff alleges that Defendant’s various consumer electronic devices containing Lithium-ion batteries infringe a patent related to improving battery capacity and performance by using a higher charge cut-off voltage in combination with a specific ratio of electrode materials.
  • Technical Context: The lawsuit concerns the fundamental chemistry and design of rechargeable Lithium-ion (Li-ion) batteries, a core technology for the multi-billion dollar portable consumer electronics market.
  • Key Procedural History: The complaint alleges that Defendant was made aware of the asserted technology via a letter dated April 21, 2021, which informed Samsung of the Chinese counterpart to the patent-in-suit. This allegation may form the basis for claims of willful infringement.

Case Timeline

Date Event
2001-09-28 Priority Date for ’641 Patent (based on Chinese application)
2010-07-06 U.S. Patent No. 7,749,641 Issued
2021-04-21 Plaintiff allegedly notified Samsung of the Chinese counterpart patent
2022-10-13 Complaint Filed

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

U.S. Patent No. 7,749,641 - "Secondary Lithium Ion Cell or Battery, and Protecting Circuit, Electronic Device, and Charging Device of the Same"

The Invention Explained

  • Problem Addressed: The patent’s background section states that the Li-ion battery industry had a well-accepted technical requirement to limit the charge cut-off voltage to no more than 4.2V (ʼ641 Patent, col. 1:45-49). This limitation was believed necessary to prevent structural damage to the battery's electrodes and decomposition of the electrolyte, which would shorten the battery's usable life (ʼ641 Patent, col. 2:41-57). However, this 4.2V ceiling meant that a significant portion of the battery's theoretical energy capacity remained unutilized (ʼ641 Patent, col. 1:40-44).
  • The Patented Solution: The invention proposes a method to increase battery capacity by elevating the charge cut-off voltage above the conventional 4.2V limit while simultaneously adjusting the ratio of positive electrode material to negative electrode material (P/N ratio) ('641 Patent, Abstract). The specification explains that by increasing the amount of negative electrode material relative to the positive material, the battery can accommodate the additional lithium ions released from the positive electrode at higher voltages without causing metallic lithium to deposit on the negative electrode, an effect that would otherwise degrade performance and cycle life ('641 Patent, col. 3:56-col. 4:5).
  • Technical Importance: This approach provided a method to increase the specific energy and average operating voltage of a Li-ion cell without substantially altering the manufacturing process or negatively impacting the battery's longevity and cycle life ('641 Patent, Abstract; col. 3:11-15).

Key Claims at a Glance

  • The complaint asserts independent claims 5 and 12 (Compl. ¶4). Claim 5 is identified as exemplary (Compl. ¶12).
  • Independent Claim 5:
    • A secondary lithium ion cell or battery, characterized in that the secondary lithium ion cell or battery
    • has a charge cut-off voltage of greater than 4.2 V but less than 5.8 V, and
    • a ratio of positive electrode material to negative electrode material of the secondary lithium ion cell or battery is from 1:1.0 to 1:2.5,
    • as calculated by a theoretic capacity with a charge cut-off voltage set at 4.2 V.
  • The complaint does not explicitly reserve the right to assert dependent claims but requests relief for infringement of "one or more claims" (Compl. ¶39).

III. The Accused Instrumentality

Product Identification

The complaint accuses a wide range of Samsung's consumer electronic products that incorporate Li-ion batteries, including smartphones (e.g., Galaxy S, A, Z, and Note Series), tablets (e.g., Galaxy Tab S Series), smartwatches (e.g., Galaxy Watch Series), and headphones (e.g., Galaxy Buds Series) (Compl. ¶17, ¶22, ¶27, ¶32). Exemplary products cited include the Galaxy S20, Galaxy Tab S7+, Galaxy Watch 4, and Galaxy Buds 2.

Functionality and Market Context

  • The accused functionality is the Li-ion battery contained within the named electronic devices. The complaint alleges these batteries are designed with specific electrochemical properties that infringe the ’641 Patent (Compl. ¶19-21, ¶24-26, ¶29-31, ¶34-36).
  • The complaint alleges these batteries possess a charging voltage above 4.2V and a specific ratio of electrode materials. For example, the complaint provides a photo of a battery for a Samsung Galaxy Tab S7+, which is labeled with a "Charging limit voltage" of 4.43V (Compl. ¶24, p. 8).
  • The complaint asserts that Li-ion batteries are essential to Samsung's ability to market and sell its popular portable electronic devices (Compl. ¶9).

IV. Analysis of Infringement Allegations

’641 Patent Infringement Allegations

Claim Element (from Independent Claim 5) Alleged Infringing Functionality Complaint Citation Patent Citation
A secondary lithium ion cell or battery... The Accused Products are, or contain, secondary Li-ion batteries. ¶19, ¶24, ¶29, ¶34 col. 5:57-61
has a charge cut-off voltage of greater than 4.2 V but less than 5.8 V The batteries in the Accused Products have a charging voltage of at least 4.4V, 4.43V, or 4.47V, depending on the product, as shown on the battery labels. For example, a photo of the Galaxy Watch 4 battery shows a "Charge Voltage" of 4.47V. ¶19, ¶24, ¶29, ¶34, p. 10 col. 7:24-28
and a ratio of positive electrode material to negative electrode material of the secondary lithium ion cell or battery is from 1:1.0 to 1:2.5, The complaint alleges the P/N ratio of the batteries in the Accused Products is between 1:1.0 and 1:2.5. ¶20, ¶25, ¶30, ¶35 col. 7:31-41
as calculated by a theoretic capacity with a charge cut-off voltage set at 4.2 V. The complaint alleges the P/N ratio is "as calculated by a theoretic capacity with a charge cut-off voltage set at 4.2 V." ¶20, ¶25, ¶30, ¶35 col. 3:5-9

Identified Points of Contention

  • Scope Questions: A potential dispute may arise over whether the term "charge cut-off voltage" as used in the patent is synonymous with the "Limited Charge Voltage" or "Charge Voltage" printed on the labels of the accused batteries (Compl. p. 8, 10, 12). The court may need to determine if the labeled value reflects the operational parameter defined by the claim.
  • Technical Questions: A primary evidentiary question is how Plaintiff will prove the P/N ratio limitation. The complaint makes a conclusory assertion that the ratio is within the claimed range (e.g., Compl. ¶20, ¶25) but provides no measurements, test data, or other factual support for this allegation. The "as calculated by" language further requires this ratio to be determined using the specific methodology disclosed in the patent, adding another layer of required proof.

V. Key Claim Terms for Construction

The Term: "charge cut-off voltage"

  • Context and Importance: This term is the lynchpin of the infringement allegation, as the invention is premised on exceeding the prior art's 4.2V limit. The infringement case hinges on whether the voltages printed on Samsung's batteries (e.g., 4.43V, 4.47V) satisfy this limitation. Practitioners may focus on this term because its definition will determine whether the plaintiff's photographic evidence is sufficient to show infringement of this element.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patent frequently discusses elevating the "charge cut-off voltage" in the context of setting a target for charging (e.g., "charge cut-off voltage of 4.35 V") and testing the cell, suggesting it is a known design parameter ('641 Patent, col. 6:57-58). This could support an argument that the maximum charging voltage printed on a battery's specification label is its "charge cut-off voltage."
    • Evidence for a Narrower Interpretation: The term could be interpreted more narrowly to mean the specific voltage at which a charging circuit actually terminates a charge cycle in practice, which is an operational value, not necessarily the maximum rated voltage on a component label. The patent's focus on a "protecting circuit" and "charging device" could support an argument that the term relates to the function of the overall system ('641 Patent, Abstract).

The Term: "ratio of positive electrode material to negative electrode material... as calculated by a theoretic capacity with a charge cut-off voltage set at 4.2 V"

  • Context and Importance: This limitation is critical because it works in tandem with the elevated voltage. Infringement requires proving not just a physical ratio of materials but that this ratio falls within the claimed range when evaluated according to the patent's specific calculation method. The complexity of this limitation presents a significant evidentiary hurdle for the plaintiff.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: A party might argue that any standard industry method for determining electrode material ratios is sufficient, as long as the 4.2V baseline is used for the capacity calculation.
    • Evidence for a Narrower Interpretation: The patent explicitly defines "theoretical capacities" as being "calculated with an charge cut-off voltage set at 4.2 V" ('641 Patent, col. 3:5-9). A party could argue this requires a specific, rigorous calculation that accounts for the unique properties of the electrode materials at that specific voltage baseline, potentially excluding simpler physical mass-based ratios.

VI. Other Allegations

Indirect Infringement

The complaint alleges inducement to infringe based on Samsung's affirmative acts of encouraging and instructing customers on how to use the Accused Products. This is supported by reference to Samsung’s advertising and marketing materials, including a screenshot from its website explaining its Li-ion battery technology (Compl. ¶40-41, p. 13).

Willful Infringement

The willfulness allegation is based on alleged pre-suit knowledge. The complaint states that on April 21, 2021, the inventors sent a letter to Samsung identifying the Chinese counterpart patent (ZL 01141615.7). This notice of the underlying technology, if proven, could support a finding of willful infringement from that date forward (Compl. ¶42-43).

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

  • A central issue will be one of evidentiary proof: The complaint provides photographic evidence for the "charge cut-off voltage" limitation but offers only conclusory statements for the "ratio of positive electrode material to negative electrode material." A key question will be what technical evidence, such as materials analysis from reverse engineering or internal Samsung documents, the plaintiff can produce to substantiate this critical and complex claim element.
  • The case may also turn on a question of definitional equivalence: Can the "Limited Charge Voltage" or "Charge Voltage" printed on Samsung's battery components be legally and technically equated to the "charge cut-off voltage" as defined by the patent claims? The outcome of this claim construction dispute could determine the relevance of the plaintiff's primary infringement evidence.