DCT

2:25-cv-01116

Bunker Hill Tech LLC v. Ford Motor Co

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:25-cv-01116, E.D. Tex., 11/10/2025
  • Venue Allegations: Plaintiff alleges venue is proper because Defendant is subject to personal jurisdiction in the district, has committed acts of infringement there, and maintains a regular and established place of business in Plano, Texas.
  • Core Dispute: Plaintiff alleges that Defendant’s electric and hybrid-electric vehicles infringe eight patents related to on-board power supplies, battery charging architectures, and power management systems.
  • Technical Context: The patents relate to the field of power electronics within electric vehicles, a domain critical for managing battery charging, efficiency, and advanced features such as providing external power from the vehicle.
  • Key Procedural History: The complaint alleges that Defendant had pre-suit knowledge of the asserted patents and infringement through a series of communications with Plaintiff's licensing agent beginning in November 2024, which included presentations and the downloading of specific claim charts from a data room.

Case Timeline

Date Event
2008-12-02 U.S. Patent No. 7,960,857 Priority Date
2011-05-02 U.S. Patent No. 8,487,582 Priority Date
2011-06-14 U.S. Patent No. 7,960,857 Issued
2013-07-16 U.S. Patent No. 8,487,582 Issued
2014-01-30 U.S. Patent No. 10,442,296 Priority Date
2015-03-13 U.S. Patent No. 9,821,668 Priority Date
2016-09-14 U.S. Patent No. 9,914,365 Priority Date
2016-11-04 U.S. Patent No. 9,809,121 Priority Date
2017-09-07 U.S. Patent No. 9,975,439 Priority Date
2017-09-07 U.S. Patent No. 10,604,023 Priority Date
2017-11-07 U.S. Patent No. 9,809,121 Issued
2017-11-21 U.S. Patent No. 9,821,668 Issued
2018-03-13 U.S. Patent No. 9,914,365 Issued
2018-04-04 U.S. Patent No. 10,604,023 Application Filed
2018-05-22 U.S. Patent No. 9,975,439 Issued
2019-10-15 U.S. Patent No. 10,442,296 Issued
2020-03-31 U.S. Patent No. 10,604,023 Issued
2024-11-20 Plaintiff alleges licensing discussions with Defendant began
2025-06-26 Plaintiff alleges Defendant downloaded claim charts for seven of the eight Asserted Patents
2025-10-22 Plaintiff alleges Defendant received a claim chart for the '365 Patent
2025-11-10 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," issued June 14, 2011

The Invention Explained

  • Problem Addressed: The patent describes systems for providing uninterruptable power from a vehicle, implying the technical challenge of managing the vehicle’s energy systems to ensure a continuous and stable supply of external power without compromising the vehicle's primary functions or battery health (’857 Patent, col. 7:6-14).
  • The Patented Solution: The invention is a vehicle-based Uninterruptable Power Supply (UPS) that uses a dedicated control system to manage the vehicle's battery and charging systems. The controller monitors the battery's state-of-charge (SOC) or voltage while it powers an external load via a DC-AC inverter. If the SOC drops below a predetermined level, the controller "selectively operate[s] the charging device" to recharge the battery, thereby maintaining an uninterruptable power supply to the external load (’857 Patent, Abstract; col. 3:10-24).
  • Technical Importance: This technology allows a vehicle to function as a smart mobile power source, actively managing its energy reserves to provide continuous power for external devices, a feature valuable for worksites, recreational activities, and emergency backup power (’857 Patent, col. 7:59-64).

Key Claims at a Glance

  • The complaint asserts at least independent claim 1 (Compl. ¶34).
  • The essential elements of independent claim 1 are:
    • A vehicle-based uninterruptable power supply (UPS) system.
    • An on-board energy storage system configured to power the vehicle's motor and auxiliary devices, and to provide DC power for an external load.
    • A DC-AC inverter to convert the DC power to AC power for the external load.
    • An on-board charging device connected to the energy storage system to provide recharging power.
    • A control system configured to cause power to be supplied to the external load, determine the energy storage system's SOC or voltage during this process, and selectively operate the charging device to maintain the SOC/voltage within a set range, ensuring uninterruptable power.

U.S. Patent No. 8,487,582 - "Apparatus for transferring energy using onboard power electronics and method of manufacturing same," issued July 16, 2013

The Invention Explained

  • Problem Addressed: The patent background notes that adding dedicated circuitry to a vehicle for the sole purpose of charging its battery from an external source (like the utility grid) adds extra cost and weight (’582 Patent, col. 1:45-55). The technical problem is how to achieve this charging function more efficiently by leveraging existing components.
  • The Patented Solution: The invention proposes using the vehicle's own on-board power electronics—specifically, a "bi-directional voltage modification assembly" (such as the inverter used for the traction motor)—to also manage the charging process from an external "high-impedance voltage source" like a grid outlet. A controller monitors the energy transfer and modifies the voltage or current to properly charge the on-board energy storage device, eliminating the need for a separate, dedicated charger (’582 Patent, Abstract; col. 4:1-14).
  • Technical Importance: This approach integrates the function of an on-board charger with the powertrain's power electronics, which can reduce the cost, weight, and complexity of electric and hybrid vehicles by reducing component redundancy (’582 Patent, col. 2:56-62).

Key Claims at a Glance

  • The complaint asserts at least independent claim 1 (Compl. ¶51).
  • The essential elements of independent claim 1 are:
    • An apparatus with an energy storage device that outputs a DC voltage.
    • A bi-directional voltage modification assembly coupled to the energy storage device.
    • A charge bus coupled to both the energy storage device and the modification assembly, where the bus is also coupleable to a "high-impedance voltage source."
    • A controller that monitors the transfer of charging energy from the high-impedance source and modifies the charging voltage or current based on this monitoring.

Multi-Patent Capsules

  • U.S. Patent No. 9,809,121, "Apparatus for energy transfer using converter and method of manufacturing same," issued November 7, 2017

    • Technology Synopsis: The patent describes a vehicle charging system that utilizes a connection system with two different connections (e.g., AC and DC) and charges an energy storage device at different rates depending on which connection is used. The system employs a plurality of DC converters to boost (step-up) an input voltage to an intermediate voltage and buck (step-down) that voltage for charging the energy storage device (Compl. ¶¶67-71).
    • Asserted Claims: At least independent claim 7 is asserted (Compl. ¶65).
    • Accused Features: The accused features are the Ford Mustang Mach-E's combined AC/DC charging port and its onboard charger, which allegedly uses a multi-stage converter architecture to manage different charging rates from AC and DC sources (Compl. ¶¶67-71).

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

    • Technology Synopsis: The patent is directed to an energy storage and management system (ESMS) for a vehicle with multiple energy storage devices (e.g., a low-voltage 12-volt battery and a high-voltage traction battery). The system uses multiple DC/DC converters and switching devices to manage charging of both batteries from either an external source or an internal source, such as regenerative braking (Compl. ¶¶82-89).
    • Asserted Claims: At least independent claim 16 is asserted (Compl. ¶81).
    • Accused Features: The complaint targets the Ford Mustang Mach-E's dual-battery architecture (12V and high-voltage) and the power control systems that manage energy flow between these batteries and from external (AC/DC charging) and internal (regenerative braking) sources (Compl. ¶¶82-83).

  • U.S. Patent No. 9,914,365, "Apparatus and method for rapid charging using shared power electronics," issued March 13, 2018

    • Technology Synopsis: This patent describes a vehicle with a connection system capable of both DC and AC charging. A controller is programmed to charge the vehicle's battery at a faster rate when using the DC connection and a slower rate with the AC connection. The system uses a plurality of onboard DC converters to step-up and step-down voltage when charging via the AC connection (Compl. ¶¶100-107).
    • Asserted Claims: At least independent claim 5 is asserted (Compl. ¶99).
    • Accused Features: The allegations focus on the Ford Mustang Mach-E's support for both DC fast charging and slower Level 2 AC charging, utilizing its onboard converter system to process the AC input (Compl. ¶¶105-107).

  • U.S. Patent No. 9,975,439, "Apparatus for energy transfer using converter and method of manufacturing same," issued May 22, 2018

    • Technology Synopsis: The patent discloses a vehicle power system architecture comprising an energy storage device, a traction drive with an inverter and motor, and an onboard charging system. The system utilizes a series of voltage converters, including a first buck DC-DC converter and a second and third boost/buck converter pair, to manage power transfer between these components (Compl. ¶¶118-124; ’439 Patent, Abstract).
    • Asserted Claims: At least independent claim 1 is asserted (Compl. ¶117).
    • Accused Features: The complaint targets the integrated power electronics of the Ford Mustang Mach-E, including the alleged use of a buck converter for the low-voltage system and a multi-stage boost/buck architecture within the onboard AC charger (Compl. ¶¶119, 123-124).

  • U.S. Patent No. 10,442,296, "Vehicle propulsion system with multi-channel DC bus and method of manufacturing same," issued October 15, 2019

    • Technology Synopsis: This invention relates to a hybrid electric vehicle system comprising an energy storage system, a bi-directional DC/DC converter, first and second traction motors, and an internal combustion engine. The system is configured with an electrically variable transmission (EVT) that includes planetary gears, and a gear assembly allows the output of the second motor to bypass the transmission device (’296 Patent, Claim 1).
    • Asserted Claims: At least independent claim 1 is asserted (Compl. ¶134).
    • Accused Features: The accused product is the Ford Escape Plug-in Hybrid, specifically its powertrain which allegedly includes an electronic continuously variable transmission (eCVT) with a power split device, two electric motor-generators, an internal combustion engine, and a bi-directional DC/DC converter (Compl. ¶¶136-140).

  • U.S. Patent No. 10,604,023, "Apparatus for energy transfer using converter and method of manufacturing same," issued March 31, 2020

    • Technology Synopsis: This patent describes a vehicle with an energy storage device, a traction drive, and an onboard charging system. The charging system includes a receptacle for an external source and uses a second voltage converter to boost an input voltage to an intermediate voltage, and a third converter to buck that intermediate voltage to charge the battery (’023 Patent, Claim 1).
    • Asserted Claims: At least independent claim 1 is asserted (Compl. ¶152).
    • Accused Features: The allegations are directed at the Ford Mustang Mach-E's onboard AC charging system, which is alleged to use a multi-stage architecture with a DC boost converter and a buck DC converter to process power from an external source (Compl. ¶¶158-159).

III. The Accused Instrumentality

Product Identification

  • The complaint identifies Ford and Lincoln branded electric and/or hybrid-electric vehicles equipped with AC power outlets or specific charging capabilities (Compl. ¶¶34, 51). The primary exemplary products are the 2025 Ford F-150 Lightning, the 2025 Ford Mustang Mach-E, and the 2025 Ford Escape Plug-in Hybrid (Compl. ¶¶34, 51, 134).

Functionality and Market Context

  • The accused functionalities center on the vehicles' advanced power management systems. For the F-150 Lightning, this includes the "Pro Power Onboard" or "Onboard Generator" feature, which allows the vehicle's high-voltage battery to supply AC power to external devices through outlets in the frunk, cabin, and bed (Compl. ¶¶35, 36). A screenshot from the vehicle's interior depicts the user interface for "Pro Power Onboard" and an adjacent AC outlet (Compl. p. 15). For the Mustang Mach-E and Escape Plug-in Hybrid, the accused functionalities relate to the architecture of their on-board charging systems for both AC and DC charging, the use of multiple converters, and the management of power between dual-battery systems (12V and high-voltage) and multiple traction motors (Compl. ¶¶53-55, 67, 83, 136-138).
  • The complaint frames these features as fundamental technologies in modern electric vehicles, enabling key capabilities such as vehicle-to-load power and efficient multi-source charging (Compl. ¶¶8, 27).

IV. Analysis of Infringement Allegations

'857 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
[a] vehicle-based uninterruptable power supply (UPS) system... The Ford F-150 Lightning includes a vehicle-based uninterruptable power supply, marketed as the "Onboard Generator." ¶35 col. 7:59-64
an energy storage system located on-board a vehicle, the energy storage system configured to provide electric power for at least one of driving an electric motor...and to also generate DC power transferable to an external load. The accused products include a high voltage lithium-ion battery that powers the vehicle's electric motor(s) and generates DC power that is transferable to an external load via on-board AC outlets. ¶36 col. 4:3-10
a 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 connected to the high voltage battery that converts DC power to AC power for use by external devices plugged into the vehicle's outlets. ¶37 col. 4:11-16
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 a regenerative braking system to capture energy during deceleration and return it to the high voltage battery, thereby providing recharging power. ¶38 col. 5:48-52
a control system configured to...cause the energy storage system to provide power transferable to the external load...determine one of a state-of-charge (SOC) and a voltage of the energy storage system...and selectively operate the charging device...to maintain the one of the SOC and the voltage...within a pre-determined range... The accused products include a control system that manages power to external devices, determines the battery's state-of-charge, and uses regenerative braking to recharge the battery to provide uninterruptable power. The complaint includes an image of the "Power Mode Indicator" which displays power usage and availability (Compl. p. 16). ¶¶39-41 col. 4:17-38
  • Identified Points of Contention:
    • Scope Questions: A central question may be whether the term "charging device" as used in the patent can be construed to encompass a "regenerative braking system" as alleged (Compl. ¶38). The patent specification provides examples such as an auxiliary power unit (APU) or a DC-DC converter (’857 Patent, col. 5:50-52, col. 6:6-8), raising the question of whether a system that recaptures kinetic energy, rather than actively generating power from a fuel source or another battery, falls within the claim's scope.
    • Technical Questions: The infringement theory hinges on the allegation that the control system "selectively operate[s]" the regenerative braking system "to maintain" the battery's state-of-charge for the external load (Compl. ¶41). A key technical question is whether the accused system's control logic actively engages regenerative braking for this specific purpose, or if the recharging is merely an incidental result of normal driving operations (e.g., slowing down) that happens to occur while an external load is connected. The complaint does not specify the mechanism by which the controller would "operate" the braking system for this maintenance function.

'582 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
an energy storage device configured to output a DC voltage. The Ford Mustang Mach-E includes a high-voltage lithium-ion battery system that stores energy and outputs DC voltage. ¶52 col. 3:9-12
a bi-directional voltage modification assembly coupled to the energy storage device. The accused products include a "bi-directional voltage converter assembly," identified by a specific part number, which is coupled to the high voltage battery. A parts diagram for this assembly is provided in the complaint (Compl. p. 22). ¶53 col. 3:13-16
a charge bus coupled to the energy storage device and to the bi-directional voltage modification assembly, the charge bus coupleable to a high-impedance voltage source. The accused products include a high voltage DC bus coupled to the battery and converter assembly, which is coupleable to an external high-impedance voltage source such as a 120V or 240V AC outlet via the vehicle's charge port. ¶54 col. 3:17-21
a controller configured to: monitor a transfer of charging energy...; and modify one of a voltage and a current of the charging energy...based on the monitored transfer... The accused products include a "Drive Motor Battery Pack Control Module" that monitors the transfer of energy to the battery and modifies the charging voltage and current to prevent overcharging and manage charging thresholds. ¶55 col. 3:22-30
  • Identified Points of Contention:
    • Scope Questions: The case may turn on the construction of "bi-directional voltage modification assembly." The patent specification describes this as a bi-directional DC-to-AC voltage inverter composed of half-phase modules (’582 Patent, col. 3:14-19). The complaint points to a "bi-directional voltage converter assembly" within a complex onboard charging architecture that includes AC-DC and DC-DC converters (Compl. p. 21). This raises the question of whether the accused multi-component charging system, as a whole, meets the definition of the single "assembly" claimed in the patent.
    • Technical Questions: The complaint alleges that the "Drive Motor Battery Pack Control Module" performs the claimed controller functions (Compl. ¶55). The analysis will require evidence of how this module technically operates to "monitor a transfer of charging energy" and "modify" the voltage or current "based on the monitored transfer," as required by the claim's specific control loop.

V. Key Claim Terms for Construction

'857 Patent, Claim 1: "charging device"

  • Context and Importance: This term's construction is critical because the infringement allegation relies on equating it with the accused product's regenerative braking system. A narrow definition could render the claim non-infringed. Practitioners may focus on this term because the patent's examples (APU, DC-DC converter) differ in function from a system that recaptures kinetic energy.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The claim language itself is broad, requiring only that the device be "located on-board" and "provide a recharging power." This language does not explicitly limit the source of that power.
    • Evidence for a Narrower Interpretation: The specification provides examples of the charging device, such as an "auxiliary power unit (APU), such as an internal combustion engine" (’857 Patent, col. 5:50-52) or a "DC-DC converter" transferring power from a higher-voltage battery (’857 Patent, col. 6:6-8). This may support an interpretation limited to devices that actively generate power or transfer it from another stored energy source, rather than recapturing it from motion.

'582 Patent, Claim 1: "bi-directional voltage modification assembly"

  • Context and Importance: The definition of this term is central to whether the accused product's onboard charger architecture infringes. The patent envisions reusing the powertrain's inverter for charging, while the accused product contains a more complex, multi-stage charging system.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The term "assembly" is general and could be argued to cover any collection of components that collectively performs bi-directional voltage modification. The function, not the specific implementation, could be argued as paramount.
    • Evidence for a Narrower Interpretation: The specification describes the assembly as a "bi-directional DC-to-AC voltage inverter" comprising "six half phase modules" (’582 Patent, col. 3:14-19). This specific embodiment could be used to argue for a narrower construction limited to a single, integrated inverter unit rather than a multi-part charging system with distinct AC-DC and DC-DC stages as depicted in the complaint (Compl. p. 21).

VI. Other Allegations

Indirect Infringement

  • The complaint alleges induced infringement for all asserted patents. The factual basis cited is Defendant's creation and dissemination of user manuals, marketing materials, and online instructional content that allegedly teach and encourage customers to use the accused features (e.g., charging the vehicle, using the onboard generator) in an infringing manner (Compl. ¶¶42-43, 56-57, 72, 90, 108, 125, 143, 160).

Willful Infringement

  • The complaint alleges willful infringement for all asserted patents, justifying enhanced damages. The basis for willfulness is alleged pre-suit knowledge. Plaintiff claims it notified Defendant of the patents and its infringement through communications beginning in November 2024, including providing claim charts that were subsequently downloaded by IP addresses associated with Defendant in June, September, and October of 2025, prior to the complaint's filing (Compl. ¶¶21-26, 45, 59).

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

  • A core issue will be one of definitional scope: can the term "charging device" in the ’857 patent, described in the context of an APU, be construed to cover the "regenerative braking system" in the accused Ford F-150 Lightning? The outcome of this claim construction dispute may be dispositive for a key part of the infringement case.
  • A second central theme will be architectural equivalence: do the multi-stage, multi-component power conversion systems in the accused Ford vehicles (e.g., the Mustang Mach-E's onboard charger) meet the limitations of claims that describe more integrated components, such as the "bi-directional voltage modification assembly" of the ’582 patent? This will likely involve a technical battle over whether the accused systems operate in a substantially similar way to what is claimed.
  • Finally, a significant question for damages will be willfulness: given the complaint's detailed allegations of pre-suit notice, including specific dates of emails and data room downloads of claim charts, the case will likely focus heavily on what Defendant knew about the patents and when, and whether its continued sales of the accused products constituted egregious conduct warranting enhanced damages.