Bunker Hill Tech LLC v. Nissan Motor Co Ltd

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Bunker Hill Technologies, LLC (Texas)
  • Defendant: Nissan Motor Co., Ltd. (Japan)
  • Plaintiff's Counsel: Nelson Bumgardner Conroy PC
• Case Identification: 2:26-cv-00231, E.D. Tex., 03/20/2026
• Venue Allegations: Plaintiff alleges venue is proper because the defendant, Nissan, is a foreign corporation and may be sued in any judicial district.
• Core Dispute: Plaintiff alleges that Defendant's electric and hybrid-electric vehicles infringe four U.S. patents related to vehicle power supply, energy management, and charging systems.
• Technical Context: The technologies at issue involve systems for using an electric vehicle as a mobile power source, optimizing energy consumption based on historical route data, and managing the charging of multiple onboard energy storage devices.
• Key Procedural History: The complaint alleges that Plaintiff's licensing agent placed Defendant on notice of infringement of the Asserted Patents beginning in March 2025 and subsequently provided claim charts demonstrating infringement for all four patents between July and November 2025, prior to the filing of the complaint.

Case Timeline

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

U.S. Patent No. 7,960,857 - "System and method for vehicle based uninterruptable power supply," issued June 14, 2011

The Invention Explained

• Problem Addressed: The patent's background section identifies the need for dependable, long-duration emergency power sources, noting that conventional Uninterruptible Power Supplies (UPS) have batteries with limited capacity, which is insufficient for critical needs like medical equipment during extended outages '857 Patent, col. 1:11-56
• The Patented Solution: The invention proposes using a vehicle's own powertrain as a long-lasting UPS '857 Patent, abstract The system utilizes the vehicle's onboard energy storage (e.g., battery) to supply DC power, an inverter to convert it to AC power for an external load, and a control system. This control system monitors the battery's state-of-charge (SOC) and automatically activates the vehicle's onboard "charging device" (e.g., an engine/alternator) to recharge the battery when its SOC falls below a predetermined level, thereby providing a continuous power supply '857 Patent, col. 4:3-29
• Technical Importance: This approach leverages the significantly larger energy generation and storage capacity of a vehicle compared to a typical standalone UPS, enabling extended operation for external loads.

Key Claims at a Glance

• The complaint asserts at least independent claim 1 Compl. ¶30
• Claim 1 includes the following essential elements:
  • A vehicle-based uninterruptable power supply (UPS) system.
  • An onboard energy storage system configured to power the vehicle and also generate DC power for an external load.
  • A DC-AC inverter to convert the DC power to AC power for the external load.
  • An onboard charging device connected to the energy storage system to provide recharging power.
  • A control system configured to:
    • Cause power to be provided to the external load via the inverter.
    • Determine the state-of-charge (SOC) or voltage of the energy storage system while it provides power.
    • Selectively operate the charging device to recharge the energy storage system to maintain its SOC/voltage within a set range.

U.S. Patent No. 8,086,364 - "System and method for operation of electric and hybrid vehicles," issued December 27, 2011

The Invention Explained

• Problem Addressed: The patent addresses the sub-optimal energy management in hybrid and electric vehicles that results from control systems lacking information about upcoming terrain or driving conditions '364 Patent, col. 1:43-52 For instance, a vehicle might begin a long downhill descent with a full battery, thereby being unable to capture available regenerative braking energy. The patent also notes the difficulty of using historical trip data due to GPS inaccuracies that prevent matching a current location with past trip records '364 Patent, col. 2:36-53
• The Patented Solution: The invention describes a system that creates and utilizes a "historical power-use database" tied to specific segments of a map, referred to as "links" '364 Patent, abstract The system identifies the vehicle's current location, applies a pre-screening algorithm to efficiently find potential map links nearby, matches the location to a specific link, and then uploads the vehicle's power consumption data for that link into the database '364 Patent, col. 10:8-23 This learned data can then be used on subsequent trips to optimize energy strategy, such as adjusting the battery's state-of-charge target in anticipation of an upcoming hill '364 Patent, col. 8:1-16
• Technical Importance: This allows the vehicle to "learn" from previous journeys on the same routes, enabling proactive and more efficient energy management to improve overall performance and extend battery life.

Key Claims at a Glance

• The complaint asserts at least independent claim 9 Compl. ¶47
• Claim 9 recites a method with the following essential steps:
  • Identifying a current location of a vehicle.
  • Applying a pre-screening algorithm with respect to a map link and the current location, where the algorithm is based on a maximum link length from a historical power-use database.
  • Determining if one or more links are within a given bounds.
  • If so, matching the vehicle's current location to the link via a subsequential matching algorithm.
  • Uploading power information used by the vehicle along that link into the historical power-use database.

U.S. Patent No. 8,326,467 - "Controller and method of controlling a power system," issued December 4, 2012

• Technology Synopsis: The patent describes a method for controlling a power system, such as in an electric vehicle, using a multi-controller architecture '467 Patent, abstract A first controller determines the operating condition of at least two power system components (e.g., a charging system and a battery) and decides whether a predetermined condition is met (e.g., a scheduled charge completion time is approaching and the battery is not yet full). Based on this determination, it transmits a command to a second controller to electrically couple or decouple the components to manage the power flow '467 Patent, col. 2:1-12
• Asserted Claims: At least claim 16 is asserted Compl. ¶62
• Accused Features: The "Charging Timer" feature in the accused vehicles, which allows users to schedule charging operations Compl. ¶63 The complaint alleges this feature uses an Engine Control Module (ECM) as a first controller and a Power Delivery Module as a second controller to manage the charging of the high-voltage battery to meet a predetermined end time Compl. ¶¶64-68 A manual excerpt in the complaint shows the user interface for setting a charging "End Time" Compl. p. 33

U.S. Patent No. 9,821,668 - "Method and apparatus for charging multiple energy storage devices," issued November 21, 2017

• Technology Synopsis: The patent discloses an Energy Storage and Management System (ESMS) for an electric vehicle designed to charge multiple, distinct energy storage devices (e.g., a low-voltage 12V battery and a high-voltage traction battery) '668 Patent, abstract The system uses a plurality of DC/DC conversion devices and switching devices to manage power flow from both an external charging source (e.g., a wall outlet) and an internal charging source (e.g., the electric motor during regenerative braking), allowing for flexible and controlled charging of the different batteries '668 Patent, col. 20:1-11
• Asserted Claims: At least claim 16 is asserted Compl. ¶78
• Accused Features: The accused vehicles' overall electric vehicle system architecture, which uses two types of batteries: a 12-volt battery and a high-voltage Li-ion battery Compl. ¶79 The complaint alleges that the vehicles' system of DC/DC converters and controllers manages charging of these two batteries from both external charging devices and internal regenerative braking, thereby infringing the patent Compl. ¶¶80-88 A vehicle manual excerpt explicitly states, "This vehicle uses two types of batteries" Compl. p. 42

III. The Accused Instrumentality

Product Identification

• The accused products are Nissan- and Infiniti-branded vehicles equipped with electric or hybrid-electric powertrain systems Compl. ¶4 The complaint specifically identifies the 2023-25 Nissan Ariya, 2018-26 Nissan Leaf, and 2026 Nissan Rogue as examples Compl. p. 2, fn. 1

Functionality and Market Context

• The complaint focuses on several key functionalities. The Vehicle-to-Load (V2L) feature allows the vehicle to act as a mobile power source, providing up to 1,500 watts of AC power to external devices, such as for camping or during a power outage Compl. ¶31 Compl. p. 8
• The navigation system, referred to as the "Intelligent Route Planner," provides route guidance that incorporates EV-specific data, such as automatically adding charging station waypoints to a route if the destination exceeds the vehicle's estimated range Compl. ¶49 Compl. ¶51 This range estimation is based on factors including past energy consumption Compl. p. 20
• A "Charging Timer" feature enables users to schedule charging sessions, for instance, to take advantage of off-peak electricity rates Compl. ¶63
• The vehicles employ a dual-battery architecture, with a main high-voltage lithium-ion battery for propulsion and a 12-volt battery for vehicle systems, with power electronics to manage charging from both external sources and regenerative braking Compl. ¶79 Compl. ¶81

IV. Analysis of Infringement Allegations

'857 Patent Infringement Allegations

• Identified Points of Contention:
  • Scope Questions: A potential point of contention may be whether "regenerative braking" constitutes the "charging device" as contemplated by the patent. The patent's specification primarily describes embodiments using an auxiliary power unit (APU) or combustion engine that can be turned on for the express purpose of maintaining charge for the UPS function '857 Patent, col. 8:1-6 The analysis may question whether a system integral to vehicle deceleration (regenerative braking) meets the claim limitation of being "selectively operate[d]... to maintain" the SOC for an external load.
  • Technical Questions: The complaint alleges that regenerative braking occurs "while power will be provided to the socket" Compl. ¶37 A technical question may arise as to the conditions under which the vehicle can simultaneously provide power to an external load and recharge via regenerative braking, and whether this operation serves to "maintain" the SOC "within a pre-determined range" for the purpose of providing uninterruptible power, as required by the claim.

'364 Patent Infringement Allegations

• Identified Points of Contention:
  • Scope Questions: The construction of the term "link" may be a central issue. The patent describes "links" as discrete segments uniquely defined by "start and end nodes" '364 Patent, col. 6:1-3 The analysis may question whether the complaint's allegations, which refer more generally to route segments and paths to charging stations, meet this potentially more specific structural definition.
  • Technical Questions: The claim requires "uploading power information used by the vehicle along the link." A key technical question will be what evidence exists that Nissan's system specifically associates power consumption data with discrete map "links" and uploads it in that format, as opposed to collecting more generalized driving history and average energy consumption data not tied to the patent's specific database structure.

V. Key Claim Terms for Construction

For the '857 Patent

• The Term: "charging device" (Claim 1)
• Context and Importance: The infringement theory hinges on mapping this term to the accused products' regenerative braking system. Practitioners may focus on this term because its construction could determine whether a system integral to EV operation (braking) falls within the scope of a claim for a system that appears to contemplate a dedicated power generation unit for a UPS function.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The claim language itself is broad, requiring only "a charging device located on-board the vehicle" without specifying its type '857 Patent, col. 14:1-3
  • Evidence for a Narrower Interpretation: The specification's embodiments repeatedly describe the charging device as an "auxiliary power unit (APU), such as an internal combustion engine" '857 Patent, col. 4:50-53 or an "engine" and "alternator" '857 Patent, FIG. 3 This focus on engine-based generators could support a narrower construction that excludes regenerative braking.

For the '364 Patent

• The Term: "historical power-use database" (Claim 9)
• Context and Importance: This term is critical because the invention is premised on a specific type of database that links power usage to map segments. The dispute will likely center on whether Nissan's system, which uses historical data to estimate range, employs the specific database structure claimed.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The claim term itself does not explicitly detail the internal data structure, which could support an argument that any database storing historical power information for use in navigation infringes.
  • Evidence for a Narrower Interpretation: The specification details a database structure organized around "links" that are "uniquely defined by start and end nodes," with associated power, speed, and frequency data ('364 Patent, col. 5:65 - col. 6:4; Table 1). This suggests a specific, structured database that may be narrower than a general collection of past driving data.

VI. Other Allegations

• Indirect Infringement: The complaint alleges induced infringement for all four patents. The allegations are based on Nissan creating and disseminating materials such as user manuals, marketing brochures, and online instructional content that allegedly teach and encourage customers to use the accused functionalities, such as V2L, intelligent route planning, and scheduled charging Compl. ¶39 Compl. ¶54 Compl. ¶70 Compl. ¶90
• Willful Infringement: Willfulness is alleged for all four patents. The complaint asserts that Nissan had pre-suit knowledge based on communications from Plaintiff's licensing agent beginning on March 3, 2025, which included the provision of detailed claim charts for the '857, '467, and '668 patents on July 21, 2025, and for the '364 patent on November 21, 2025 Compl. ¶¶20-22 Compl. ¶41 Compl. ¶56 Compl. ¶72 Compl. ¶92

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

• A core issue will be one of technical and functional scope: for the '857 patent, can a vehicle's standard regenerative braking system, which is integral to driving, be construed as the claimed "charging device" that is "selectively operate[d]" to provide "uninterruptable power" to an external load, a function the patent appears to attribute to a dedicated generator?
• A second key question will be evidentiary and structural: for the '364 patent, what evidence demonstrates that Nissan's navigation system utilizes the specific "historical power-use database" structure-organized by discrete "links" and "nodes"-recited in the patent, as opposed to a more generalized system for learning from past energy consumption that is technically distinct?
• A broader theme across the case may be one of temporal scope: does the language of patents filed between 2008 and 2015, which describe earlier generations of hybrid and electric vehicle technology, read on the integrated and complex energy management systems found in modern EVs like the Nissan Ariya and Leaf?