DCT
3:24-cv-08441
Shenzhen Jinliheng E Commerce Co Ltd v. Guangdong Miyear Mgxon Power System Co Ltd
Key Events
Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Shenzhen Jinliheng E-commerce Co., Ltd. and Anyangshiyuantukejiyouxiangongsi (China)
- Defendant: Guangdong Miyear Mgxon Power System Co., Ltd. (China)
- Plaintiff’s Counsel: Ziqi Yu
- Case Identification: Shenzhen Jinliheng E-commerce Co., Ltd. et al v. Guangdong Miyear Mgxon Power System Co., Ltd., 3:24-cv-08441, N.D. Cal., 11/26/2024
- Venue Allegations: Plaintiffs allege venue is proper because a substantial part of the events, including sales of the Accused Products and the effects of Defendant's patent enforcement activity, occurred in the district. Venue is also asserted on the basis that the Defendant is a foreign corporation.
- Core Dispute: Plaintiffs seek a declaratory judgment that their lithium battery products do not infringe Defendant's patent related to a universal rechargeable battery and control method, following Defendant's patent infringement complaints submitted to Amazon.com.
- Technical Context: The technology concerns rechargeable lithium-ion batteries that incorporate internal control circuitry to manage charging and discharging, allowing them to function as direct replacements for common, lower-voltage consumer batteries.
- Key Procedural History: The action was precipitated by Defendant's patent infringement complaints to Amazon.com on or about November 6, 2024, which Plaintiffs claim are inaccurate. The complaint notes that the patent-in-suit was assigned to the Defendant on October 14, 2024, shortly before the enforcement activity began.
Case Timeline
| Date | Event |
|---|---|
| 2013-09-23 | ’412 Patent Priority Date |
| 2018-10-16 | ’412 Patent Issue Date |
| 2024-10-14 | ’412 Patent Assignment to Defendant Recorded |
| 2024-11-06 | Defendant Submits Infringement Complaints to Amazon.com |
| 2024-11-26 | Complaint for Declaratory Judgment Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 10,103,412 - “Universal Rechargeable Battery Constituted by Employing Lithium-Ion Battery and Control Method,” issued October 16, 2018
The Invention Explained
- Problem Addressed: The patent describes the difficulty of using high-voltage lithium-ion batteries (e.g., 3.2V-3.8V) as direct substitutes for common universal batteries that operate at lower voltages like 1.5V or 1.2V (Compl., Ex. 1, ’412 Patent, col. 1:16-31). It also identifies deficiencies in prior art solutions, such as the lack of integrated charging control, temperature protection, and the risk of cell damage from over-charging or over-discharging (’412 Patent, col. 2:14-34).
- The Patented Solution: The invention is a self-contained rechargeable battery that pairs a lithium-ion cell with an integrated charging/discharging controller circuit inside a standard battery housing (’412 Patent, Abstract). This controller includes a DC-DC step-down regulator to deliver a constant, lower output voltage (e.g., 1.5V) and circuitry to manage the charging process, monitor battery voltage, and provide temperature protection, as illustrated in the circuit diagram of Figure 54 (’412 Patent, col. 4:13-35, Fig. 54).
- Technical Importance: This integrated approach allows a high-energy-density lithium-ion cell to serve as a safe, high-performance, drop-in replacement for conventional primary or Ni-H batteries in a wide range of consumer devices (’412 Patent, col. 4:5-12).
Key Claims at a Glance
- The complaint seeks a declaratory judgment of non-infringement of independent claims 1 and 5 (Compl. ¶¶ 19, 24).
- Independent Claim 1 recites a method for controlling the battery, comprising the key steps of:
- Providing a control circuit with a charging circuit, a detection circuit, and a DC-DC step-down regulator.
- During charging, detecting the battery's output voltage to select a charging scheme (e.g., constant-current).
- During discharging, detecting the battery's output voltage to perform a regulated voltage output, which involves stepping down the voltage to different levels or cutting it off based on whether the battery's voltage is above or below a low power threshold (V_L) and a discharge cutoff threshold (V_D).
- Independent Claim 5 recites a more detailed control method comprising seven distinct "control conditions," including detecting the connection of a power source, selecting a charging scheme based on battery voltage, managing disconnection from the charger, regulating discharge voltage based on multiple thresholds, and cutting off charging or discharging based on temperature detection.
III. The Accused Instrumentality
Product Identification
- The Accused Products are "lithium batteries sold by Plaintiffs on Amazon.com" under ASINs B0D1VHTLCS, B0D4M581B3, and B0D4M3D4L9 (Compl. ¶2).
Functionality and Market Context
- The complaint alleges that the Accused Products are lithium batteries that regulate their discharge using a method different from that claimed in the ’412 Patent (Compl. ¶24). Specifically, Plaintiffs contend that their products "regulate their discharge by detecting the current and the state of charge (SOC)," in contrast to the patent's method of detecting output voltage (Compl. ¶24).
- The complaint includes a redacted webpage printout from an Amazon.com listing for one of the Accused Products (Compl. ¶2, Ex. 3).
- The products are sold on Amazon.com, and Plaintiffs allege that Defendant's enforcement activity creates an "imminent danger of the removal of items and cessation of sales," particularly given the approaching Black Friday sales period (Compl. ¶4).
IV. Analysis of Infringement Allegations
The complaint does not contain a claim chart. The central non-infringement argument is presented in prose. The table below summarizes the Plaintiffs' stated theory of non-infringement with respect to a key limitation of the asserted claims.
’412 Patent Non-Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Non-Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| during a discharging status, the lithium-ion battery charging/discharging control circuit detects the output voltage of the lithium-ion battery, and performs a regulated voltage output... | The Accused Products regulate their discharge by detecting the current and the state of charge (SOC). | ¶24 | col. 5:36-39 |
- Identified Points of Contention:
- Technical Question: The core of the dispute is a factual one: what technical parameter do the Accused Products' control circuits measure to regulate discharge? The case will likely turn on evidence establishing whether the circuits operate by directly comparing battery voltage to set thresholds (as the patent describes) or by using a different method, such as coulomb counting (integrating current over time) to determine the state of charge (SOC).
- Scope Questions: The dispute raises the question of whether "detects the output voltage" can be interpreted to cover the functions allegedly performed by the Accused Products. Defendant may argue that determining SOC necessarily involves or is equivalent to a voltage measurement, while Plaintiffs will likely contend that detecting "current and the state of charge" is a distinct and non-equivalent technical approach.
V. Key Claim Terms for Construction
- The Term: "detects the output voltage of the lithium-ion battery"
- Context and Importance: This phrase appears in both independent claims 1 and 5 and is the foundation of the non-infringement theory advanced in the complaint. The definition of this term will be critical because Plaintiffs' position is that their products use an entirely different method (detecting current and SOC) to achieve discharge regulation.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: A party could argue for a broader meaning by pointing to specification language that links voltage levels to the battery's state of charge. For example, the patent defines V_L as a "low power voltage of the lithium-ion battery set by the voltage detection circuit" (’412 Patent, col. 15:4-7). This might be used to argue that any method that determines the battery has reached a "low power" state, regardless of the specific technique, falls within the claim's scope.
- Evidence for a Narrower Interpretation: A party could argue for a narrower meaning by highlighting that the patent's disclosed embodiment and control methods consistently describe a direct comparison of the battery's real-time output voltage against predefined voltage thresholds (e.g., V_L and V_D) (’412 Patent, col. 5:36-50; col. 32:9-25). The explicit allegation that the accused products detect "current and the state of charge" (Compl. ¶24) may be used to argue for a specific technical alternative (e.g., coulomb counting) that is not merely detecting voltage.
VI. Other Allegations
- Indirect Infringement: The complaint includes a general denial of any direct or indirect infringement (Compl. ¶23). It does not, however., provide specific facts or allegations related to indirect infringement, as the pleading's focus is on establishing the absence of direct infringement.
VII. Analyst’s Conclusion: Key Questions for the Case
- A central evidentiary question of technical operation: Does the control circuitry in the Plaintiffs' accused batteries function by directly detecting and comparing the battery's output voltage to predefined thresholds, as taught in the ’412 patent, or does it employ a fundamentally different technique, such as one based on monitoring current and calculating state-of-charge, as the complaint alleges?
- A core issue of claim construction: Can the claim term "detects the output voltage of the lithium-ion battery" be construed broadly to encompass methods of determining state-of-charge that may use current measurements as an input, or is the term limited to the direct voltage-threshold-comparison method explicitly described in the patent's specification?