WSOU Investments LLCv. OnePlus Technology

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: WSOU Investments, LLC d/b/a Brazos Licensing and Development (Delaware)
  • Defendant: OnePlus Technology (Shenzhen) Co., Ltd. (China)
  • Plaintiff’s Counsel: Rabicoff Law LLC
• Case Identification: 6:20-cv-00957, W.D. Tex., 10/14/2020
• Venue Allegations: Venue is asserted on the basis that the Defendant has allegedly committed acts of patent infringement in the district and maintains an established place of business there.
• Core Dispute: Plaintiff alleges that Defendant’s products, which include battery-powered electronics, infringe a patent related to methods for estimating the remaining time to fully charge a rechargeable battery.
• Technical Context: The technology concerns accurately predicting battery charging time in portable devices by distinguishing between different phases of the charging cycle, a feature of significant importance for user experience in the consumer electronics market.
• Key Procedural History: The complaint does not reference any prior litigation, Inter Partes Review (IPR) proceedings, or licensing history related to the patent-in-suit.

Case Timeline

Date	Event
2010-10-25	’708 Patent Priority Date
2014-04-29	’708 Patent Issue Date
2020-10-14	Complaint Filing Date

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

• Patent Identification: U.S. Patent No. 8,712,708, “Method of estimating remaining constant current/constant voltage charging time,” issued April 29, 2014.

The Invention Explained

• Problem Addressed: The patent's background section notes that "typical battery chargers do not provide a reliable estimate of the remaining charging time needed until the battery is charged to its maximum capacity" (’708 Patent, col. 1:23-27).
• The Patented Solution: The invention is a method for more accurately estimating the remaining charge time by treating the two primary phases of modern battery charging—constant current (CC) and constant voltage (CV)—differently. The system first determines which phase the battery is currently in. If in the CC phase, it calculates the time needed to complete that phase plus the expected duration of the entire subsequent CV phase. If already in the CV phase, it calculates only the time remaining in that phase. (’708 Patent, Abstract; Fig. 5). This approach relies on using "pre-determined battery charging characteristics" to inform the calculations (’708 Patent, col. 2:1-9).
• Technical Importance: By creating a more sophisticated estimation model that adapts to the charging phase, the invention sought to provide users of portable devices with a more dependable "time to full" display. (’708 Patent, col. 1:23-27).

Key Claims at a Glance

• The complaint alleges infringement of "Exemplary '708 Patent Claims" but incorporates these claims by reference to an exhibit that was not included with the public filing (Compl. ¶11, ¶17). The analysis below is based on representative independent claim 1.
• The essential elements of independent claim 1 include:
  • Detecting the availability of a charger adapter.
  • Determining if the battery is in a "constant current phase" or a "constant voltage phase" based on "pre-determined battery charging characteristics."
  • If in the constant current phase, calculating a time remaining based on "constant current phase charging characteristics."
  • If in the constant voltage phase, calculating a time remaining based on "constant voltage phase charging characteristics."
  • The claim further specifies that the calculation in the constant current phase is based on "stored charge characteristics" derived from "monitored tracking of battery charging and discharging."
• The complaint’s assertion of "one or more claims" suggests it reserves the right to assert additional claims, including dependent claims (Compl. ¶11).

III. The Accused Instrumentality

Product Identification

• The complaint identifies infringement by "Exemplary Defendant Products," which are detailed in charts incorporated by reference from an external exhibit not attached to the complaint (Compl. ¶11, ¶17).

Functionality and Market Context

• The complaint alleges that these products "practice the technology claimed by the '708 Patent" (Compl. ¶17). This implies the accused products contain battery management systems that estimate and display remaining charge time. However, the complaint does not provide specific details regarding the technical operation of the accused charging algorithms or their market positioning, deferring all such allegations to the unattached Exhibit 2.

IV. Analysis of Infringement Allegations

The complaint alleges that the "Exemplary Defendant Products" satisfy all elements of the asserted claims, but it provides no specific factual allegations in the body of the complaint to construct a narrative infringement theory (Compl. ¶17). Instead, it incorporates by reference claim charts from an unattached "Exhibit 2" (Compl. ¶18). Without access to this exhibit, a detailed claim chart analysis cannot be performed.

No probative visual evidence provided in complaint.

• Identified Points of Contention: Based on the claim language and the general nature of the allegations, the dispute may focus on several technical and legal questions:
  • Scope Questions: Do the accused products' methods for estimating charge time fall within the scope of the patent's two-phase (CC/CV) calculation method? For instance, do the accused devices truly distinguish between the phases for calculation purposes as claimed, or do they use a different, unified model?
  • Technical Questions: What evidence demonstrates that the accused products use "pre-determined battery charging characteristics" and "stored charge characteristics based on monitored tracking," as required by claim 1? The case may require a detailed examination of the accused devices' software and hardware to determine how their algorithms function.

V. Key Claim Terms for Construction

"pre-determined battery charging characteristics"

• Context and Importance: This term appears central to defining how the patented method is implemented. The infringement analysis will depend on whether the accused devices use data that meets this definition to distinguish between the CC and CV phases. Practitioners may focus on this term because its construction could either limit the patent to specific data structures or allow it to cover a wider range of battery modeling techniques.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The term itself does not explicitly require a specific format. An argument could be made that any battery characteristic data that is established prior to the real-time calculation, including dynamically learned models, qualifies as "pre-determined."
  • Evidence for a Narrower Interpretation: The specification repeatedly refers to pre-measured data sets unique to a device and battery combination, such as "data set 215 of data points for values of stored battery charge...versus remaining charging time" and "data set 210...for values of charging current...versus remaining charging time" (’708 Patent, col. 7:7-14; Fig. 3). This suggests "pre-determined" may be construed more narrowly to mean static, factory-loaded lookup tables or profiles.

"stored charge characteristics...based on monitored tracking of battery charging and discharging"

• Context and Importance: This wherein clause of claim 1 adds a specific requirement for the calculation performed during the constant current phase. Plaintiff must prove that the accused devices use a characteristic that is not just a simple real-time measurement (like voltage) but is based on a history of monitoring the battery's charge and discharge cycles.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The language could be argued to cover any algorithm that uses a running estimate of battery capacity, a common feature in modern battery management.
  • Evidence for a Narrower Interpretation: The specification describes this in detail as maintaining "an updated value for the present stored charge CAP in the battery" by continuously monitoring the device to "keep track of both discharging the battery 160, as well as charging the battery" (’708 Patent, col. 9:28-34). This could support an interpretation requiring a specific type of coulomb-counting or capacity-tracking algorithm.

VI. Other Allegations

• Indirect Infringement: The complaint alleges both induced and contributory infringement. Inducement is premised on Defendant distributing "product literature and website materials" that allegedly instruct users to operate the products in an infringing manner (Compl. ¶14). Contributory infringement is alleged on the basis that the accused products are "especially made or adapted for infringing" and have "no substantial non-infringing use" because they contain functionality material to the claims (Compl. ¶16).
• Willful Infringement: The willfulness allegation is based on post-suit conduct. The complaint asserts that the "service of this Complaint upon Defendant constitutes actual knowledge" and that Defendant continues to infringe "Despite such actual knowledge" (Compl. ¶13-14). No allegations of pre-suit knowledge are made.

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

• A core issue will be one of evidentiary proof: Given the complaint’s complete reliance on an unattached exhibit, the primary question is whether Plaintiff can produce sufficient technical evidence from the accused devices' source code or operation to demonstrate that they actually perform the specific two-phase calculation method recited in the asserted claims.
• The case will also likely depend on claim construction: The viability of the infringement claim will turn on the court's interpretation of "pre-determined battery charging characteristics." A central question will be whether this term is limited to the static, pre-loaded data tables described in the patent's embodiments or can be construed more broadly to encompass other battery modeling techniques used in modern smartphones.
• A final key question relates to infringement theory: Does the accused functionality in OnePlus devices map onto the patent's specific method of calculating remaining time based on "stored charge characteristics" during the CC phase and a different calculation for the CV phase, or is there a fundamental mismatch in the underlying technical approach to the problem?