DCT
3:25-cv-00548
Cheng USA Inc v. Kunshan Jinhui New Energy Technology Co Ltd
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Cheng USA, Inc. d/b/a Arterra Distribution and WFCO Technologies (Indiana)
- Defendant: Kunshan Jinhui New Energy Technology Co., Ltd. d/b/a Bestrenogy (China)
- Plaintiff’s Counsel: Vorys, Sater, Seymour and Pease LLP
- Case Identification: 3:25-cv-00548, U.S. District Court for the Northern District of Indiana (IN/ND), 06/25/2025
- Venue Allegations: Plaintiff alleges venue is proper because a substantial part of the events giving rise to the claims occurred in the district, and alternatively, because Defendant is a foreign entity subject to personal jurisdiction in the district.
- Core Dispute: Plaintiff alleges that Defendant’s battery charger infringes a patent related to automatically identifying battery types to optimize charging, and further alleges false advertising and unfair competition.
- Technical Context: The technology concerns smart battery chargers capable of automatically detecting the chemistry of a connected battery (e.g., lead-acid vs. lithium) to apply the correct charging profile, a critical function for battery longevity and safety.
- Key Procedural History: The complaint alleges that Defendant’s product is a near-identical copy of Plaintiff's own commercial product, including its physical design, components, and model number. In addition to patent infringement, the complaint includes counts for false advertising under the Lanham Act based on allegedly deceptive labeling and copied certifications. Plaintiff reserves the right to assert additional claims of the patent.
Case Timeline
| Date | Event |
|---|---|
| 2020-06-05 | U.S. Provisional Application No. 63/035,096 filed (Earliest Priority Date for '377 Patent) |
| 2020-10-15 | '377 Patent application filed |
| 2023-04-28 | Defendant allegedly began doing business in the U.S. |
| 2024-10-08 | U.S. Patent No. 12,113,377 issued |
| 2025-06-25 | Complaint filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 12,113,377 - "BATTERY CHARGER WITH AUTOMATIC BATTERY TYPE IDENTIFICATION"
The Invention Explained
- Problem Addressed: The patent addresses the risk of battery damage that occurs when chargers require users to manually select the correct charging settings for different battery chemistries, such as lead-acid and lithium. An incorrect setting can harm the battery or reduce its lifespan. (’377 Patent, col. 1:46-57).
- The Patented Solution: The invention is an automated battery charger that distinguishes between battery types by analyzing their electrical behavior during the charging process. Specifically, it monitors the rate at which the charge current decreases (or voltage increases) as the battery nears full charge. The patent discloses that different battery types, like lithium and lead-acid, exhibit measurably different rates of change, allowing the charger to automatically identify the connected battery and apply the optimal charging profile without user input. (’377 Patent, Abstract; col. 4:8-15). The distinct charging curves for lithium (FIG. 1) and lead-acid (FIG. 2) illustrate this core principle.
- Technical Importance: This automation improves safety and maximizes battery performance and longevity by eliminating the potential for user error in selecting a charge profile. (’377 Patent, col. 1:50-62).
Key Claims at a Glance
- The complaint asserts direct infringement of at least independent claim 10 and induced infringement of at least independent claim 20 (Compl. ¶¶ 28, 56).
- Independent Claim 10 (Apparatus): The essential elements are:
- a controlled voltage source to apply power to a battery;
- means for identifying a first battery type when the rate of change of current/voltage near charge completion is greater than a threshold;
- means for identifying a second battery type when the rate of change of current/voltage near charge completion is less than a threshold; and
- means for controlling the voltage or current based on the identified battery type.
- Independent Claim 20 (Method): The essential elements are:
- monitoring the charging voltage or current;
- identifying a first battery type when the rate of voltage increase near charge completion is greater than a threshold;
- identifying a second battery type when the rate of voltage increase near charge completion is less than a threshold;
- setting a charging profile based on the identified type; and
- charging the battery according to that profile.
- The complaint reserves the right to assert infringement of additional patent claims (Compl. p. 4, fn. 1).
III. The Accused Instrumentality
Product Identification
- The accused product is the "9855-AD-CB Battery Charger 9800 Series" sold by Defendant under the "BESTRENOGY" brand (the "Infringing Model") (Compl. ¶27).
Functionality and Market Context
- The complaint, citing the product's Amazon page, describes the Infringing Model as an "advanced three-level automatic conversion charger with automatic detection technology that can detect battery types and automatically adjust charging modes" (Compl. ¶29).
- Plaintiff alleges the Infringing Model is an intentional copy of its own WF-9855 battery charger, claiming it uses the "same board design, components, and construction" (Compl. ¶33). A side-by-side photograph provided in the complaint shows the internal circuit board layout of the Plaintiff's charger and the accused Infringing Model, alleging they are visually identical (Compl. p. 10).
- The Infringing Model is allegedly sold in the U.S. through e-commerce platforms including Amazon and eBay (Compl. ¶6).
IV. Analysis of Infringement Allegations
’377 Patent Infringement Allegations (Claim 10)
| Claim Element (from Independent Claim 10) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a controlled voltage source configured to apply electrical power to a battery to be charged | The Infringing Model is described as an "automatic conversion charger" that applies power to a battery. | ¶29 | col. 6:58-62 |
| means for identifying the battery to be charged as a first battery type when... a rate at which the charge current decreases or a rate at which the charge voltage increases is greater than a threshold value | The Infringing Model has "automatic detection technology that can detect battery types." The complaint provides a charging waveform from the product for a lead-acid battery (first type) as evidence of this function. | ¶30 | col. 6:1-6 |
| means for identifying the battery to be charged as a second battery type when... the rate at which the charge current decreases or the rate at which the charge voltage increases is less than the threshold value | The Infringing Model's "automatic detection technology" allegedly performs this function. The complaint provides a charging waveform from the product for a lithium battery (second type) as evidence. | ¶31 | col. 6:1-6 |
| means for controlling one or more of voltage or current of the controlled voltage source... based on identification of the battery type | The Infringing Model "automatically adjust[s] charging modes" to specific voltage levels (e.g., "float," "absorption," "bulk") based on the detected battery type. | ¶32 | col. 6:1-6 |
’377 Patent Infringement Allegations (Claim 20)
| Claim Element (from Independent Claim 20) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| monitoring one or more of charging voltage or charging current of a battery to be charged | The Infringing Model allegedly "detect[s] battery types" and has an "electronic current limiter," which requires monitoring current and voltage. | ¶35 | col. 6:28-31 |
| identifying the battery to be charged as a first battery type when... a rate at which the charge voltage increases is greater than a threshold value | The Infringing Model's "automatic detection technology" allegedly performs this step, as evidenced by a charging waveform for a lead-acid battery. | ¶36 | col. 7:31-40 |
| identifying the battery to be charged as a second battery type when... the rate at which the charge voltage increases is less than the threshold value | The Infringing Model's "automatic detection technology" allegedly performs this step, as evidenced by a charging waveform for a lithium battery. | ¶37 | col. 7:41-51 |
| setting a charging profile based on the identified battery type... | The product is alleged to "automatically adjust charging modes" based on the detected type. | ¶38 | col. 2:36-39 |
| charging the battery to be charged as a function of the charging profile | The product is alleged to charge batteries using different modes (e.g., bulk, absorption, float) based on the detected type. | ¶38 | col. 2:36-39 |
- Identified Points of Contention:
- Scope Questions: Claim 10 uses means-plus-function language ("means for identifying..."). A central issue for the court will be construing these terms under 35 U.S.C. § 112(f). This involves identifying the corresponding structure in the patent specification—the processor 314 executing the specific algorithm of FIG. 4—and then determining if the accused device's internal structure and software are identical or structurally equivalent. The complaint’s allegation that the Infringing Model uses the "same board design, components, and construction" directly frames this as a structural equivalence dispute (Compl. ¶33).
- Technical Questions: The claims require identifying battery type based on a measured "rate" of change. A key evidentiary question is whether the accused product's "automatic detection technology" actually performs the specific function of analyzing the rate of change of current or voltage, as required by the claims. The complaint’s evidence relies on marketing materials and output waveforms (Compl. ¶¶ 29-31, Exs. 5-6), which raises the question of whether this is sufficient to show the device’s internal operating method, or if an alternative, non-infringing detection method is used.
V. Key Claim Terms for Construction
The Term: "means for identifying the battery..." (Claim 10)
- Context and Importance: As a means-plus-function limitation, the scope of this term is not the literal words but the corresponding structure disclosed in the patent. Practitioners may focus on this term because its construction is dispositive for infringement. The dispute will center on whether the accused product's processor and software constitute an equivalent structure to what is disclosed in the patent.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: A party might argue the corresponding structure is the "processor 314" generally, as it is the component that performs the function (’377 Patent, col. 6:1-6).
- Evidence for a Narrower Interpretation: A party could argue the structure is not just the processor, but the processor specifically configured to execute the algorithm shown in the flowchart of FIG. 4, which details a multi-step process of timing current drops between thresholds (’377 Patent, FIG. 4; col. 6:53-7:51).
The Term: "a rate at which the charge current decreases or a rate at which the charge voltage increases" (Claims 10, 20)
- Context and Importance: The definition of "rate" is critical for determining if the accused device performs the claimed method. Infringement hinges on whether the accused product actually calculates or measures this characteristic.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification suggests this can be a measurement of the time it takes for current to fall between two fixed points (e.g., 20 amps to 5 amps), which is a proxy for rate (’377 Patent, col. 5:9-25).
- Evidence for a Narrower Interpretation: The specification also uses the term "slope" when describing the voltage rise, which may suggest a more formal calculation of a derivative (ΔV/Δt or ΔI/Δt) is required, rather than simply measuring the time elapsed over a set interval (’377 Patent, col. 5:32-40).
VI. Other Allegations
- Indirect Infringement: The complaint alleges inducement of infringement of method claim 20, asserting that Defendant encourages customers to use the Infringing Model's automatic detection features as advertised, knowing this use constitutes infringement (Compl. ¶¶ 55-58).
- Willful Infringement: The complaint alleges willfulness based on at least post-suit knowledge via service of the complaint (Compl. ¶59). However, the pleading also provides a basis for alleging pre-suit willfulness by asserting that the Infringing Model is a direct and intentional copy of Plaintiff's commercial product, including its model number, internal design, and labeling (Compl. ¶¶ 33, 39, 40). A visual in the complaint compares the product labels, alleging the Infringing Model uses deceptively similar contact information and certification marks to mislead consumers (Compl. ¶40, p. 13).
VII. Analyst’s Conclusion: Key Questions for the Case
- A central issue will be one of structural equivalence under 35 U.S.C. § 112(f). The complaint alleges the accused product contains an "identical 'means'" for performing the claimed functions. The key question for the court is whether the circuitry and software of the accused device are structurally identical or equivalent to the specific algorithm-programmed processor disclosed in the '377 patent’s specification.
- A key evidentiary question will be one of operational proof: does the evidence show that the accused charger’s "automatic detection technology" actually operates by measuring the "rate of change" of current or voltage as required by the claims, or does it use an alternative, non-infringing method to differentiate battery types?
- Given the strong allegations of direct product copying, a significant aspect of the case will be whether the alleged "deceptive acts" can support not only the parallel Lanham Act claims but also a finding of pre-suit "willful infringement", which would expose the Defendant to the risk of enhanced damages.