DCT
1:23-cv-00911
NOCO Co v. Shenzhen Carku Technology Co Ltd
Key Events
Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: The NOCO Company (Ohio)
- Defendant: Shenzhen CARKU Technology Co., Ltd. (China)
- Plaintiff’s Counsel: Jones Day
- Case Identification: 1:23-cv-00911, N.D. Ill., 02/14/2023
- Venue Allegations: Plaintiff alleges venue is proper because Defendant is subject to personal jurisdiction in the district, with a substantial portion of events giving rise to the claims occurring there, including sales of accused products to Illinois residents via online platforms like Amazon.com and Newegg.com. The complaint also notes that Defendant previously initiated its own patent litigation in this district, suggesting purposeful availment.
- Core Dispute: Plaintiff alleges that Defendant’s portable vehicle jump starters infringe three U.S. patents related to battery cell equalization circuits and USB charging technology.
- Technical Context: The technology concerns compact, high-power, lithium-ion-based portable jump starters, a consumer electronics category that replaced older, bulkier lead-acid systems.
- Key Procedural History: The complaint alleges that the parties have a history of litigation, with Plaintiff having previously accused Defendant of infringing a related patent (U.S. Patent No. 9,007,015) in proceedings before the U.S. International Trade Commission, the Patent Trial and Appeal Board, and the U.S. Court of Appeals for the Federal Circuit. This history is cited to support allegations of willful infringement.
Case Timeline
| Date | Event |
|---|---|
| 2017-03-31 | Earliest Priority Date for ’452 and ’213 Patents |
| 2018-03-15 | Earliest Priority Date for ’023 Patent |
| 2021-04-20 | Issue Date for U.S. Patent No. 10,981,452 |
| 2022-02-22 | Issue Date for U.S. Patent No. 11,254,213 |
| 2022-09-20 | Issue Date for U.S. Patent No. 11,447,023 |
| 2022-10-01 | Approximate date of accused product listings cited in the complaint |
| 2023-02-14 | Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 10,981,452 - "Portable or Hand Held Vehicle Battery Jump Starting Apparatus with Battery Cell Equalization Circuit"
The Invention Explained
- Problem Addressed: The patent addresses the risk that in a multi-cell lithium-ion battery pack, individual cells can become overcharged during the charging process, which can lead to overheating, fire, and reduced battery life (Compl. ¶ 21; ’452 Patent, col. 4:40-48).
- The Patented Solution: The invention is a battery cell equalization circuit that monitors the voltage of each individual cell in the battery pack. If a cell's voltage exceeds a predetermined upper threshold, the circuit discharges that specific cell through a load resistor. This slows its charging rate relative to the other cells, allowing lower-voltage cells to "catch up" and ensuring all cells reach a full charge in a balanced state ('452 Patent, col. 9:41-54, Fig. 5).
- Technical Importance: This technology was intended to improve the safety and operational lifetime of increasingly popular compact, high-power lithium-ion jump starters (Compl. ¶ 19, 21).
Key Claims at a Glance
- The complaint asserts Independent Claim 1 (Compl. ¶ 33).
- Essential elements of Claim 1 include:
- A portable or hand held jump starting apparatus.
- A battery with a plurality of individual battery cells connected in series.
- A battery cell equalization circuit connected to the battery, which itself comprises an individual equalization circuit and a load resistor for each battery cell.
- The individual circuits are configured to discharge a cell via its load resistor when its voltage exceeds an upper threshold, continuing until it reaches a lower threshold or charging terminates.
- The circuits are also configured to charge lower-voltage cells at a higher rate, allowing them to catch up to the highest-voltage cell.
- The complaint alleges infringement of "one or more claims" of the patent (Compl. ¶ 31).
U.S. Patent No. 11,254,213 - "Portable or Hand Held Vehicle Battery Jump Starting Apparatus with Battery Cell Equalization Circuit"
The Invention Explained
- Problem Addressed: As a continuation of the same patent family, the ’213 Patent addresses the same technical challenge as the ’452 Patent: preventing cell imbalance and overcharging in lithium-ion battery packs used in portable jump starters (’213 Patent, col. 3:40-48).
- The Patented Solution: The patent describes a functionally identical battery cell equalization circuit that actively balances the charge across multiple cells by monitoring individual cell voltages and discharging any cell that exceeds a specific threshold (’213 Patent, Abstract; col. 9:35-48). The core inventive concept is consistent with the parent ’452 Patent.
- Technical Importance: The technology provides a method for enhancing the safety and reliability of portable jump starters by mitigating the inherent risks of charging multi-cell lithium-ion batteries (Compl. ¶ 21).
Key Claims at a Glance
- The complaint asserts Independent Claim 1 (Compl. ¶ 42).
- Essential elements of Claim 1 include:
- A portable or hand held jump starting apparatus.
- A battery with a plurality of individual battery cells connected in series.
- A battery cell equalization circuit connected to the battery, comprising a plurality of individual equalization circuits and a plurality of load resistors, one for each cell.
- The circuits are configured to discharge a cell via its load resistor when its voltage exceeds an upper threshold, continuing until it reaches a lower voltage level or charging terminates.
- The complaint alleges infringement of "one or more claims" of the patent (Compl. ¶ 43).
U.S. Patent No. 11,447,023 - "Portable Vehicle Battery Jump Start Apparatus with Safety Protection and Jumper Cable Device Thereof"
- Technology Synopsis: This patent addresses the problem of recharging jump starters, which previously often required proprietary, high-power chargers (Compl. ¶ 24). The invention provides a circuit, including a DC/DC converter, that allows the device's internal high-voltage battery to be recharged using a standardized, low-voltage USB power source ('023 Patent, col. 4:55-65).
- Asserted Claims: Independent Claim 1 (Compl. ¶ 50).
- Accused Features: The complaint alleges that the accused products' USB input circuits, DC/DC converters, and USB input connectors infringe the ’023 Patent (Compl. ¶¶ 58-60).
III. The Accused Instrumentality
Product Identification
- The complaint identifies "the CARKU jump starters," including four specific models: the CARKU X6 12V 10000mAh, a 2000A Peak 20000mAh model, the Audewdirect Jump Starter 1500A Peak Current (Epower-172), and the Audewdirect Car Jump Starter Portable Auto Battery Booster 1000A Peak (Epower-146b) (Compl. ¶ 29). The complaint provides representative images of four accused jump starter models (Compl. ¶ 35).
Functionality and Market Context
- The accused products are described as portable, lithium-ion battery-based devices used to jump-start vehicles (Compl. ¶¶ 35, 44). The complaint alleges, upon information and belief, that these devices contain internal battery cell equalization circuits that perform the functions claimed in the ’452 and ’213 Patents (Compl. ¶¶ 37-39, 46-47). It further alleges they contain USB input circuits with DC/DC converters for recharging, which are accused of infringing the ’023 Patent (Compl. ¶¶ 58-59). A screenshot of an accused product highlights its USB ports, including USB Type-C connections (Compl. ¶ 58). Plaintiff characterizes Defendant as a "principal copycat" whose products are sold on major U.S. online marketplaces (Compl. ¶ 2).
IV. Analysis of Infringement Allegations
10,981,452 Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a portable or hand held jump starting apparatus... | The accused CARKU jump starters are described as portable or hand held jump starting apparatuses. | ¶35 | col. 9:28-30 |
| a battery comprising a plurality of individual battery cells connected together in series; | The accused products contain a lithium-ion battery, which upon information and belief comprises a plurality of individual cells connected in series. | ¶36 | col. 9:31-33 |
| a battery cell equalization circuit connected to the battery, the battery cell equalization circuit comprising: an individual battery cell equalization circuit provided for each... and a load resistor provided for each... | Upon information and belief, the accused products contain a battery cell equalization circuit with an individual circuit and load resistor for each cell. | ¶37 | col. 9:34-40 |
| wherein the individual battery cell equalization circuits are configured to discharge a respective individual battery cell... upon the respective individual battery cell reaching a cell voltage exceeding a pre-determined upper voltage threshold until the respective cell reaches a pre-determined lower voltage level... | Upon information and belief, the internal circuits discharge a cell when its voltage exceeds an upper threshold until it reaches a lower threshold. | ¶38 | col. 9:41-48 |
| wherein the individual battery cell equalization circuits are configured to charge lower voltage individual battery cells at a higher rate allowing lower voltage individual battery cells to catch up... | Upon information and belief, the circuits are configured to allow lower-voltage cells to charge faster and catch up to higher-voltage cells. | ¶39 | col. 9:49-54 |
11,254,213 Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A portable or hand held jump starting apparatus... | The accused CARKU jump starters are described as portable or hand held jump starting apparatuses. | ¶44 | col. 11:2-3 |
| a battery comprising a plurality of individual battery cells connected in series; | The accused products are alleged to contain a lithium-ion battery with a plurality of individual cells connected in series. | ¶45 | col. 11:4-6 |
| a battery cell equalization circuit connected to the battery, the battery cell equalization circuit comprising: a plurality of individual battery cell equalization circuits each provided for each respective battery cell; and a plurality of load resistors each provided for each respective battery cell, | Upon information and belief, the accused products contain a battery cell equalization circuit with a plurality of individual circuits and load resistors. | ¶46 | col. 11:7-13 |
| wherein the individual battery cell equalization circuits are configured to discharge an individual battery cell by its particular load resistor upon the individual battery cell reaching a cell voltage exceeding a pre-determined upper voltage threshold until the individual battery cell reaches a pre-determined lower voltage level... | Upon information and belief, the internal circuits discharge a cell using a load resistor when its voltage exceeds an upper threshold until it reaches a lower threshold. | ¶47 | col. 11:14-20 |
- Identified Points of Contention:
- Technical Questions: The infringement allegations for the ’452 and ’213 Patents rely entirely on "information and belief" regarding the internal operation of the accused products' circuitry (Compl. ¶¶ 37, 46). The complaint cites generic marketing terms like "over charge protection" and "over discharge protection" as inferential support (Compl. ¶¶ 39, 47). A central question will be whether discovery reveals that the accused products' safety circuits perform the specific functions claimed, such as discharging a cell between a pre-determined upper and lower voltage threshold, or if they operate in a fundamentally different manner.
- Scope Questions: The functional language "configured to charge lower voltage individual battery cells at a higher rate" ('452 Patent, Claim 1) may be a point of dispute. A question for the court is whether this requires an active charging control mechanism or if it is merely an inherent, passive result of discharging the highest-voltage cell, a process the patent describes as "slowing down the effective charging rate" of that cell ('452 Patent, col. 9:50-54).
V. Key Claim Terms for Construction
The Term: "battery cell equalization circuit"
Context and Importance: This term is the heart of the asserted claims in the ’452 and ’213 Patents. The outcome of the infringement analysis will likely depend on whether the generic "safety technology" and "over charge protection" allegedly present in the accused products (Compl. ¶¶ 39, 47) falls within the scope of this term.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent states that the invention provides "battery equalization circuits, for example, with electronic apparatus having multiple Li-ion batteries" (’452 Patent, col. 4:56-58), which could be argued to support a meaning covering a general class of balancing circuits.
- Evidence for a Narrower Interpretation: The specification discloses a very specific embodiment comprising comparators, voltage references, and load resistors arranged in a particular configuration to create a discharge "hysteresis" band ('452 Patent, col. 10:39-42, Fig. 5). This detailed disclosure may be used to argue that the term should be limited to circuits with these specific structural and functional characteristics, not just any circuit that provides some form of overcharge protection.
The Term: "configured to charge lower voltage individual battery cells at a higher rate"
Context and Importance: This functional limitation in Claim 1 of the ’452 Patent is critical because the complaint does not allege any specific facts about how the accused products actively manage charging rates. Practitioners may focus on this term because its interpretation will determine what level of technical proof is required from the Plaintiff.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The claim uses the word "allowing," and the specification explains that bleeding charge from a high-voltage cell "will slow down the effective charging rate of that cell while charging the lower voltage cells at a higher rate" ('452 Patent, col. 9:50-54). This could support an interpretation where the "higher rate" is a passive consequence of the claimed discharging function, not a separately required active function.
- Evidence for a Narrower Interpretation: The term could be interpreted to require a circuit that does more than just slow down one cell, but actively directs more charging current to other cells. The absence of such an active charging controller in the accused products would support a non-infringement argument under this narrower construction.
VI. Other Allegations
- Willful Infringement: The complaint alleges willful infringement for all three patents.
- For the ’452 and ’213 Patents, the allegations are based on the defendant's status as a competitor, public knowledge of NOCO's patent portfolio, and alleged "actual knowledge" prior to the lawsuit (Compl. ¶¶ 64, 70).
- For the ’023 Patent, the allegation is additionally supported by reference to extensive prior litigation between the parties involving a related patent, including proceedings at the ITC, PTAB, and Federal Circuit (Compl. ¶ 76). This history is presented as evidence that Defendant was aware of Plaintiff's patenting activities in this specific technological field.
VII. Analyst’s Conclusion: Key Questions for the Case
- A central issue will be one of technical proof: Can Plaintiff demonstrate through discovery that the accused products' generic "overcharge protection" features perform the specific, multi-step balancing and discharging functions recited in the asserted equalization claims, or is there a fundamental mismatch in their technical operation? The complaint's reliance on "information and belief" for all internal functionality makes this a critical hurdle.
- The case will also likely turn on a question of definitional scope: Will the term "battery cell equalization circuit" be construed broadly to encompass any circuit that balances cell voltages, or will it be limited to the specific comparator-and-resistor-based embodiment detailed in the patent specification?
- Finally, a key question for damages will be willfulness: Does the extensive prior litigation between the parties on a related patent establish that Defendant's alleged infringement of these subsequently-issued patents was objectively reckless, potentially justifying an award of enhanced damages?