DCT

2:26-cv-00230

Bunker Hill Tech LLC v. Nissan Motor Co Ltd

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:26-cv-00230, E.D. Tex., 07/29/2026
  • Venue Allegations: Venue is alleged to be proper because the Defendant, Nissan Motor Co., Ltd., is a foreign corporation, which may be sued in any judicial district under 28 U.S.C. § 1391(c)(3).
  • Core Dispute: Plaintiff alleges that Defendant's electric and hybrid-electric vehicles, including the Nissan Leaf and Ariya, infringe four U.S. patents related to vehicle power management, uninterruptible power supply functionality, route planning, and charging systems.
  • Technical Context: The technology at issue involves core functionalities of modern electric vehicles (EVs), including vehicle-to-load (V2L) power export, intelligent route planning based on historical energy use, and management of multi-battery charging systems.
  • Key Procedural History: The complaint alleges that the Plaintiff, through its licensing agent, put Nissan on notice of potential infringement as early as March 2025 and subsequently provided claim charts for the asserted patents months before filing the lawsuit, which may be significant for the Plaintiff's claims of willful infringement.

Case Timeline

Date Event
2008-12-02 Priority Date for U.S. Patent No. 7,960,857
2010-03-09 Priority Date for U.S. Patent No. 8,086,364
2011-06-14 U.S. Patent No. 7,960,857 Issued
2011-09-06 Priority Date for U.S. Patent No. 8,326,467
2011-12-27 U.S. Patent No. 8,086,364 Issued
2012-12-04 U.S. Patent No. 8,326,467 Issued
2015-03-13 Priority Date for U.S. Patent No. 9,821,668
2017-11-21 U.S. Patent No. 9,821,668 Issued
2019-01-01 Assumed Launch of 2020 Nissan Leaf Models
2021-01-01 Assumed Launch of 2022 Nissan Ariya Models
2025-03-03 Plaintiff's agent allegedly contacted Nissan regarding a potential license
2025-07-21 Plaintiff's agent allegedly provided claim charts for '857, '467, '668 patents
2025-08-04 Nissan allegedly responded that a review of materials was in progress
2025-11-21 Plaintiff's agent allegedly provided claim charts for the '364 patent
2026-07-29 Complaint Filed

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

U.S. Patent No. 7,960,857 - "System and method for vehicle based uninterruptable power supply"

The Invention Explained

  • Problem Addressed: The patent describes the need for a dependable, long-lasting source of emergency power during utility grid failures, noting that conventional Uninterruptible Power Supplies (UPS) have limited energy storage and that generators can be impractical. U.S. Patent No. 7,960,857, col. 1:10-52
  • The Patented Solution: The patent proposes using a vehicle's own powertrain as a mobile UPS. The system uses an on-board energy storage system (e.g., the main traction battery) and a DC-AC inverter to supply AC power to an external load. A control system monitors the battery's state-of-charge (SOC) and, if it falls below a predetermined level, activates an on-board "charging device" (such as an engine-driven alternator) to recharge the battery, thereby providing a continuous and long-lasting power source. U.S. Patent No. 7,960,857, abstract U.S. Patent No. 7,960,857, col. 4:1-24
  • Technical Importance: This technology effectively turns a vehicle into a large-capacity, mobile power generator, offering significantly more energy and longer-duration backup power than typical portable UPS systems. U.S. Patent No. 7,960,857, col. 2:57-62

Key Claims at a Glance

  • The complaint asserts at least independent claim 1. Compl. ¶49
  • The essential elements of independent claim 1 are:
    • A vehicle-based uninterruptable power supply (UPS) system comprising:
    • an energy storage system located on-board a vehicle, configured to provide electric power for driving an electric motor and powering auxiliary devices, and to generate DC power transferable to an external load;
    • a DC-AC inverter connected to the energy storage system to receive and invert DC power to AC power for the external load;
    • a charging device located on-board the vehicle and connected to the energy storage system to provide recharging power; and
    • a control system configured to determine the state-of-charge (SOC) or voltage while providing power to the external load, and to selectively operate the charging device to maintain the SOC or voltage within a predetermined range.
  • The complaint does not explicitly reserve the right to assert other dependent claims for this patent.

U.S. Patent No. 8,086,364 - "System and method for operation of electric and hybrid vehicles"

The Invention Explained

  • Problem Addressed: Conventional vehicle control schemes operate with limited or no information about the environment or terrain, leading to suboptimal use of energy storage. This can result in missed opportunities for regenerative braking or unnecessary battery depletion. U.S. Patent No. 8,086,364, col. 2:4-18
  • The Patented Solution: The patent discloses a system for creating and using a historical power-use database. As a vehicle travels, the system identifies its location on a map, segments the journey into "links," and uploads power usage data associated with those links to a database. For subsequent trips, the system can access this historical data to predict energy needs and optimize the use of the energy storage system. U.S. Patent No. 8,086,364, abstract U.S. Patent No. 8,086,364, col. 3:6-14
  • Technical Importance: This invention enables predictive, learning-based energy management for vehicles, allowing for improved efficiency, increased range, and extended battery life by optimizing performance based on real-world historical data for specific routes. U.S. Patent No. 8,086,364, col. 2:19-35

Key Claims at a Glance

  • The complaint asserts at least independent claim 9. Compl. ¶69
  • The essential elements of independent claim 9 are:
    • A method of energy management comprising:
    • identifying a current location of a vehicle;
    • applying a pre-screening algorithm to a map link based on a maximum link length of a historical power-use database;
    • determining if links are within given bounds;
    • if so, matching the current location to a map link via a subsequential matching algorithm; and
    • uploading power information used by the vehicle into the historical power-use database.
  • The complaint does not explicitly reserve the right to assert other dependent claims for this patent.

U.S. Patent No. 8,326,467 - "Controller and method of controlling a power system"

Technology Synopsis

The patent addresses the control of complex power systems, such as those in EVs with scheduled charging. The invention describes a method where a first controller determines the operating condition of multiple power system components (e.g., a charger and a battery) and identifies if a predetermined condition is met (e.g., a scheduled charge completion time). Based on this determination, it transmits a command to another controller to electrically couple or decouple components to manage power flow and meet the condition. U.S. Patent No. 8,326,467, abstract

Asserted Claims & Accused Features

  • Asserted Claims: The complaint asserts at least independent claim 16. Compl. ¶87
  • Accused Features: The "Charging Timer" feature in Nissan vehicles, which allows users to schedule when the vehicle battery charges, is accused of infringement. Compl. ¶¶90; Compl. ¶92

U.S. Patent No. 9,821,668 - "Method and apparatus for charging multiple energy storage devices"

Technology Synopsis

The patent describes a system for managing the charging of multiple, distinct energy storage devices within a vehicle, such as a low-voltage 12-volt battery and a high-voltage traction battery. The invention uses a configuration of multiple DC/DC converters and switching devices that allows charging from both external sources (e.g., a wall plug) and internal sources (e.g., regenerative braking from the motor), with a control system that directs power flow between the sources and the different batteries. U.S. Patent No. 9,821,668, abstract

Asserted Claims & Accused Features

  • Asserted Claims: The complaint asserts at least independent claim 16. Compl. ¶106
  • Accused Features: The energy storage and management system in Nissan EVs, which includes a 12-volt battery and a high-voltage Li-ion battery, is accused of infringement. The complaint points to the use of a plurality of DC/DC converters and switching devices to manage charging of both batteries from external and internal (regenerative braking) sources. Compl. ¶¶109-118

III. The Accused Instrumentality

Product Identification

The complaint identifies "Nissan- or Infiniti-branded vehicle[s] having electric or hybrid-electric powertrain systems" as the Accused Products. Compl. ¶4 Specific examples provided include the 2022-25 Nissan Ariya, 2020-26 Nissan Leaf, and 2026 Nissan Rogue. Compl. ¶4, fn 1

Functionality and Market Context

  • The complaint focuses on several key functionalities. For the '857 Patent, it highlights the Vehicle-to-Load (V2L) feature, which allows the vehicle to act as a "personal, portable power bank" by supplying up to 1,500 watts of AC power to external household appliances. Compl. ¶53 A screenshot from Nissan's website shows a vehicle powering camping equipment. Compl. p. 19
  • For the '364 Patent, the allegations center on the "Intelligent Route Planner." This navigation system uses GPS to find the vehicle's location and calculates driving range "based on the actual average energy consumption of previous journeys" to automatically add charging stations to a route if needed. Compl. ¶¶72-73 Compl. ¶33 A screenshot shows the vehicle's navigation system suggesting chargers along a route. Compl. p. 35
  • For the '467 Patent, the "Charging Timer" feature is accused, which allows a user to schedule start and end times for charging. Compl. ¶90 Compl. ¶47
  • For the '668 Patent, the core electrical architecture is accused, which uses both a 12-volt battery for systems like audio and a high-voltage Li-ion battery for propulsion, with various converters managing charging from both external plugs and internal regenerative braking. Compl. ¶¶109-111

IV. Analysis of Infringement Allegations

'857 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
an energy storage system located on-board a vehicle... configured to provide electric power for at least one of driving an electric motor of the vehicle and powering auxiliary devices of the vehicle and to also generate DC power transferable to an external load The Accused Products include a lithium-ion battery that powers the electric motor, auxiliary devices, and generates DC power for an external load via V2L functionality. ¶53 col. 3:12-21
an DC-AC inverter connected to the on-board energy storage system to receive the DC power therefrom and invert the DC power to an AC power useable by the external load The Accused Products include a DC-AC inverter to convert the battery's DC power to AC power for the external load, as used in the V2L feature. ¶54 col. 3:45-50
a charging device located on-board the vehicle and connected to the on-board energy storage system to provide a recharging power thereto The Accused Products use regenerative braking to charge the battery, which the complaint alleges is an on-board charging device. ¶55 col. 3:22-26
a control system configured to... determine one of a state-of-charge (SOC) and a voltage of the energy storage system while the energy storage system is providing power to the external load The Accused Products include a control system that determines and displays the battery's state-of-charge while the vehicle is in use and providing power. A screenshot shows the SOC display. ¶57 col. 4:1-12
and selectively operate the charging device... to maintain the one of the SOC and the voltage... within a pre-determined range while still providing power to the external load... The Accused Products are alleged to use regenerative braking to recharge the battery while the vehicle is in use, thereby maintaining the SOC while power is being provided. ¶58 col. 4:13-24
  • Identified Points of Contention:
    • Scope Question: A potential dispute may arise over the definition of "charging device." The patent's specification primarily describes an auxiliary power unit (APU) or engine-alternator as the charging device. U.S. Patent No. 7,960,857, col. 5:18-22 The complaint alleges that "regenerative braking" meets this limitation. Compl. ¶55 The case may raise the question of whether regenerative braking, a function tied to the vehicle's deceleration, can be "selectively operated" to "maintain" the SOC for an external load in the uninterruptible manner contemplated by the patent.
    • Technical Question: The claim requires the control system to operate the charging device to maintain SOC while providing power to the external load. What evidence does the complaint provide that the accused product's control system actively uses regenerative braking for the specific purpose of maintaining battery charge for a V2L load, as opposed to it being a general function of EV driving?

'364 Patent Infringement Allegations

Claim Element (from Independent Claim 9) Alleged Infringing Functionality Complaint Citation Patent Citation
identifying a current location of a vehicle The Accused Products identify the vehicle's current location using GPS. ¶72 col. 3:1-2
applying a pre-screening algorithm with respect to a link within a map and the current location, the pre-screening algorithm based on a maximum link length of a historical power-use database The accused navigation system gathers data (e.g., EV range) and applies a pre-screening algorithm (e.g., best-first search) based on historical power use to determine if a charging stop is needed. ¶73 col. 3:2-7
determining if one or more links are within a given bounds The accused system determines if a road segment to a charging station is within a given bound (e.g., close to the navigation route). ¶74 col. 3:7-8
if one or more links are within a given bounds, then matching the current location of the vehicle to the link within the map via a subsequential matching algorithm The accused system matches the vehicle's current location and map link to gather relevant data (e.g., range, power consumption) to determine if a stop is needed. ¶75 col. 3:8-11
uploading power information used by the vehicle along the link and at the current location into the historical power-use database The Accused Products are alleged to upload power information (e.g., state of charge, charging history) to a historical power-use database. The complaint cites the vehicle's privacy policy. ¶76 col. 3:11-14
  • Identified Points of Contention:
    • Scope Question: A central issue will be the scope of "historical power-use database." The complaint cites marketing materials stating the system calculates range based on "actual average energy consumption of previous journeys." Compl. ¶33 This raises the question of whether a simple rolling average of past consumption constitutes the structured, link-based database described in the patent's specification. U.S. Patent No. 8,086,364, col. 5:50-68
    • Technical Question: The complaint alleges the system applies "pre-screening" and "subsequential matching" algorithms. Compl. ¶¶73; Compl. ¶75 What evidence does the complaint provide that the accused navigation system's process for suggesting charging stations performs these specific algorithmic steps as claimed, rather than a more generic route-planning function?

V. Key Claim Terms for Construction

  • '857 Patent, Claim 1:

    • The Term: "charging device"
    • Context and Importance: The infringement theory hinges on equating "regenerative braking" with the claimed "charging device." Compl. ¶55 The patent specification, however, heavily features an auxiliary power unit or engine/alternator as exemplary embodiments. '857 Patent, Figs. 3, 4 Practitioners may focus on this term because its construction will determine whether a fundamental aspect of EV operation falls within the scope of a claim seemingly written for hybrid vehicles with independent power generators.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The claim itself broadly recites "a charging device located on-board the vehicle," without limiting it to a specific type like a combustion engine. '857 Patent, col. 13:62-65 This language may support an argument that any on-board mechanism that recharges the battery, including regenerative braking, is covered.
      • Evidence for a Narrower Interpretation: The detailed description repeatedly refers to activating a "combustion engine" or an "APU" to provide recharging power. ('857 Patent, col. 5:18-22; col. 8:20-25). This consistent focus on a separate, activatable power source could be used to argue that the term "charging device" should be construed more narrowly to require such a unit, potentially excluding regenerative braking which is tied to the vehicle's motion.

  • '364 Patent, Claim 9:

    • The Term: "historical power-use database"
    • Context and Importance: The viability of the infringement claim depends on whether Nissan's system, which allegedly uses "average energy consumption of previous journeys" Compl. ¶33, constitutes the claimed "historical power-use database." The construction of this term will be critical to determining if there is a technical match.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The term itself is not explicitly defined, and one could argue that any stored record of past energy use, even a simple average, qualifies as a "historical power-use database."
      • Evidence for a Narrower Interpretation: The specification provides a detailed structure for the database, describing how data is segmented into "links" uniquely defined by "start and end nodes," with associated power, speed, and frequency data. '364 Patent, col. 5:50-col. 6:15 This detailed description suggests a specific, structured database organized by map topology, which may support a narrower construction that excludes a simple, non-geolocated average of past energy consumption.

VI. Other Allegations

  • Indirect Infringement: For each of the four asserted patents, the complaint alleges induced infringement under 35 U.S.C. § 271(b). The allegations are based on Nissan allegedly instructing and encouraging infringement through the dissemination of "user manuals," "marketing materials," and "online instructional materials" that teach customers how to use the accused features (e.g., V2L, Intelligent Route Planner, scheduled charging). Compl. ¶¶59-60 Compl. ¶¶77-78 Compl. ¶¶96-97 Compl. ¶¶119-120
  • Willful Infringement: The complaint alleges willful infringement for all asserted patents. The basis for this claim is alleged pre-suit knowledge stemming from communications between Plaintiff's licensing agent and Nissan. These communications allegedly began in March 2025 and included providing Nissan with infringement claim charts for all four asserted patents between July and November 2025, well before the complaint was filed. Compl. ¶¶39-41 Compl. ¶63 Compl. ¶81 Compl. ¶100 Compl. ¶123

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

  • A core issue will be one of definitional scope: can "regenerative braking," an inherent function of an EV's traction motor during deceleration, be construed as the "charging device" that is "selectively operated" as contemplated by the '857 patent, which primarily describes an independent, activatable power unit like an engine or APU for maintaining uninterruptible power?
  • A key evidentiary question will be one of functional equivalence: does the accused vehicles' use of "average energy consumption of previous journeys" to estimate range constitute the structured, map-link-based "historical power-use database" required by the '364 patent, or is there a fundamental mismatch in the technical operation of the energy management systems?
  • A significant issue for damages will be willfulness: given the complaint's detailed allegations of pre-suit communications, including the provision of specific infringement charts, the court will likely focus on whether Nissan's continued sales of the accused products after these notices constituted objective recklessness, potentially exposing it to enhanced damages.
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