CyboEnergy, Inc. v. Duracell Power Center, LLC

I'll research this case thoroughly using web searches.

Let me dig deeper into the parties, docket status, and related proceedings.

Let me check the docket status and parallel PTAB proceedings.

Case Overview: CyboEnergy, Inc. v. Duracell Power Center, LLC, No. 5:24-cv-08891 (N.D. Cal.)

The parties. CyboEnergy, Inc. is not a classic shell NPE: it is a Rancho Cordova, California operating company and affiliate/subsidiary of CyboSoft, General Cybernation Group Inc. (founded 1994), which develops, manufactures and sells "CyboInverter" solar power mini-inverters — 4-channel, panel-level-MPPT inverters positioned between string inverters and microinverters, marketed as UL1741-certified and made in the USA, with CEO Dr. George Cheng as its public face. The company has won Frost & Sullivan and Solar Power World top-inverter recognition and openly offers IP licensing; at the same time, Unified Patents' PATROLL program classifies CyboEnergy as an "NPE" because of its serial assertion activity. It is represented here by Houston-based Ramey LLP (Jennifer L. Ishimoto signed the complaint, Dkt. 1), a firm known for high-volume patent-plaintiff work. The defendant is Duracell Power Center, LLC — the Duracell-branded residential energy line run by San Jose, CA–based Power Center / "Power Center+", an authorized licensee of Duracell (press releases describe the entity as "Power Center LLC" and "Power Center+"), which launched the "Duracell Home Ecosystem" of microinverters, LFP storage, Level 2 EV charging and a monitoring app in 2022 and distributes through BayWa r.e. and others. In other words, the target is a brand licensee, not Duracell itself.

The accused technology and patents. The accused instrumentalities are Duracell Power Center's solar microinverters — the D1500 (D1500-M4 quad) and D700 (D700-M2 dual) (the family also includes the D350-M1 single). These are multi-input microinverters serving one, two or four PV modules with independent per-module MPPT, LED status indicators and app-based commissioning/monitoring — an architecture that maps onto the asserted claims. The complaint broadly identifies "Duracell PC's solar power inverters" and reserves the right to assert additional claims and products. U.S. Patent No. 9,331,488 ("Enclosure and message system of smart and scalable power inverters"; filed June 29, 2012; issued May 3, 2016) is an LED "message system" in which a microcontroller monitors the inverter system and each DC input channel and drives a system-status LED plus per-channel LEDs (colors/flashing patterns) to signal operational states; the complaint asserts independent method claim 16, which requires the system LED to indicate five states — working, working-with-warnings, inverter errors, AC-grid errors, and off. U.S. Patent No. 9,331,489 ("Maximizing power production at low sunlight by solar power mini-inverters"; filed March 7, 2013; issued May 3, 2016) claims a multi-channel inverter with a DC power combiner, a microcontroller that runs in "normal or low power mode" based on calculated DC input power, and a DC power supply that can draw from a "dedicated input channel" when input power drops below a threshold — keeping the inverter harvesting at sunrise/sunset/partial shading. The complaint asserts independent claim 14 and dependent claims 15–16. (Note: a W.D. Tex. opinion excerpt recites a December 27, 2016 issue date for the '489; multiple other sources say May 3, 2016 — a discrepancy I could not resolve.) Sibling patent US 8,786,133 ("Smart and scalable power inverters") is co-asserted in the parallel campaign and shares claim language with the '489.

Posture and venue. Filed December 10, 2024 in the Northern District of California, docketed as 3:24-cv-08891 (San Francisco Division) by PACER-derived aggregators though shown as 5:24-cv-08891 (San Jose) by others, with a jury demand and Exhibits A–D (patents plus claim charts, Dkt. 1). It was assigned to Magistrate Judge Lisa J. Cisneros, with an initial case management conference set for March 13, 2025 and a consent/declination deadline of December 26, 2024 (Dkt. 7). Venue was essentially uncontestable: the accused products are manufactured by the defendant in San Jose (N.D. Cal.) and CyboEnergy is a California plaintiff, so a §1400(b) challenge would be weak — notable because this is one of the few CyboEnergy suits not filed in Texas. N.D. Cal. also imposes its Patent Local Rules (early infringement contentions, claim-construction exchange). Status caveat: the case metadata says "pending," but Patexia reports the case as "Dismissed – Voluntarily" with a termination date of March 13, 2025, and the Ex Parte AI docket summary lists it as "Closed"; I could not confirm this on PACER, and a Rule 41(a) voluntary dismissal would fit the campaign's dismissal-and-refiling pattern.

Why it is notable. CyboEnergy is running a broad enforcement campaign across the residential microinverter market — prior/pending actions against Altenergy Power Systems (APsystems), Northern Electric Power Technology (NEP), Aptos Solar, Hoymiles, Sensata, Yotta Energy (W.D. Tex., Aug. 13, 2025), Deye ESS/Ningbo Deye (C.D. Cal. No. 2:25-cv-07964, Aug. 22, 2025, asserting the '133 and '488 patents against SUN-series microinverters), and Generac Power Systems (W.D. Tex. No. 4:26-cv-07159). It has even sued Home Depot, per Unified Patents. Defensive activity is substantial: Unified Patents' PATROLL has posted $2,000 crowdsourced prior-art bounties targeting claim 14 of the '489 and claim 16 of the '488 (current window Sept. 14–Oct. 17, 2026); at least one PTAB petition, IPR2024-00360, names Altenergy Power System USA as petitioner, and its docket materials reference the W.D. Tex. claim-construction decision in CyboEnergy v. Altenergy, No. 6:22-cv-01136-KC (Dec. 20, 2023), which construed '489 claim 14 and addressed indefiniteness of terms such as "DC power combiner . . . for combining DC output from all DC-DC boosters," "constructed to run the power inverter in normal or low power mode based on calculated DC input power," and "configured to take DC power from a dedicated input channel." Because these patents recite fairly generic multi-channel MPPT / low-power-mode / LED-status architectures, they potentially reach most 2- and 4-input microinverters sold by Enphase's challengers — which explains the PATROLL and IPR activity. The Duracell suit is separately notable for putting a consumer battery brand's licensee in the crosshairs and for pitting a small "made in the USA" operating company against larger competitors.

Sourcing caveats. (1) The voluntary-dismissal/termination date of March 13, 2025 rests on Patexia and Ex Parte AI aggregators, not on a court order I could retrieve; treat the "pending" metadata as suspect. (2) The San Francisco (3:24) vs. San Jose (5:24) division split reflects inconsistent aggregator numbering. (3) I could not verify IPR2024-00360's challenged patent, institution status, or outcome, nor whether Duracell itself filed any IPR. (4) Claim-chart Exhibits B and D were not publicly available, so the infringement theory is drawn from the complaint narrative as summarized by third-party complaint-analysis services; the accused-product/claim mapping above is an inference from public product specs (dual/quad inputs, per-module MPPT, LED status), not from the sealed charts.

I'll research this case across dockets, PTAB, and legal news sources.

Let me dig into subsequent docket activity, PTAB proceedings, and disposition.

Let me confirm the dismissal and check for any related filings or PTAB activity.

I'll research the counsel of record for CyboEnergy in this case.

Let me dig deeper into the specific attorneys and firm details.

Now let me verify the docket entries and whether Ramey appeared in this specific case.

Counsel of Record — Plaintiff CyboEnergy, Inc.

Important framing caveat up front. The records I can retrieve for this docket are thin. The publicly mirrored docket (Justia, UniCourt, RPX Empower) is current only through December 11–12, 2024 — i.e., the pleading-stage entries. Only one attorney has a confirmed appearance on the docket in this case. In addition, secondary databases (Patexia, Ex Parte) report a termination date of March 13, 2025 with a status of "Dismissed – Voluntarily"/"Closed" — the same date the court had set for the initial case management conference (Dkt. 7). That conflicts with the case metadata here ("pending"); I flag it rather than resolve it, and note that if a voluntary dismissal occurred, no litigation-stage appearances by additional counsel would ever have been filed.

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1. Jennifer L. Ishimoto — Counsel of record / local (California) counsel

Sourcing: Justia docket for 3:24-cv-08891 (dockets.justia.com/docket/california/candce/3:2024cv08891/440883); UniCourt case page (lists "Plaintiff Attorney: Jennifer L. Ishimoto" and her ECF signature blocks); the filed complaint itself, which carries her signature block and office address (cdn.lawlytics.com/law-media/uploads/2360/314067/original/CyboEnergy-v.-Duracell.pdf).

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2. William P. Ramey III — Lead counsel (Ramey LLP), appearance not confirmed on this docket

Sourcing: Ramey LLP firm announcement, "CyboEnergy Files Patent Infringement Lawsuit Against Duracell Power Center" (rameyfirm.com), which states CyboEnergy "represented by Ramey LLP" filed in N.D. Cal. on 12/10/2024 and is authored by William P. Ramey III; Law360 firm/attorney page listing William P. Ramey III on CyboEnergy, Inc. v. Generac Power Systems, Inc. (S.D. Tex., 830 Patent), indicating an ongoing Ramey–CyboEnergy engagement; his standard PHV papers in Cooperative Entertainment v. Alibaba Cloud (N.D. Cal. 5:25-cv-01842, Dkt. 16) listing Ms. Ishimoto as local co-counsel; ABA Journal / Reuters reporting on the VDPP fee sanction.

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3. Other plaintiff-side counsel

• Patexia reports two (2) plaintiff attorneys for this case, which is consistent with Ishimoto + Ramey, but I could not verify a second Ramey attorney (e.g., another associate such as Jeffrey E. Kubiak, who has appeared with Ramey elsewhere) on this docket.
• No in-house counsel for CyboEnergy, Inc. appears anywhere in the retrievable record.
• No defense-side counsel of record appears in the retrievable docket either — no answer, appearance, or motion by Duracell Power Center is shown before the docket mirrors stop.

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Bottom line

For CyboEnergy, Inc., the only confirmed attorney of record is Jennifer L. Ishimoto of Banie & Ishimoto LLP (Palo Alto, CA), who filed the complaint and is the sole ECF filer listed. William P. Ramey III of Ramey LLP (Houston, TX) is the firm's stated counsel for this suit and should be treated as the likely lead counsel, but his appearance (or a pro hac vice application) is not confirmed in the records available to me — and given the reported 3/13/2025 voluntary dismissal (Patexia; Ex Parte "Closed"), such an application may never have been filed. If you need certainty on Ramey's appearance, a PACER pull of the full docket sheet for 5:24-cv-08891 after 12/12/2024 is required, since the free mirrors are stale and I found no sealed-filing indication either way.

I'll research the docket and counsel appearances for this case.

Bottom line

No counsel of record for Duracell Power Center, LLC is identifiable in this case — and the reason appears to be that no defendant-side attorney ever entered an appearance. The docket reflects only plaintiff-side filings, and the case was terminated by voluntary dismissal roughly three months after filing, before any defendant responsive deadline or appearance.

I want to be explicit per your instructions: I am not going to name any attorney as "defendant's counsel" here, because the record I can access does not support one. Everything below is what the record does and does not show.

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What the public docket shows

The case was filed December 10, 2024 as CyboEnergy, Inc. v. Duracell Power Center, LLC, No. 3:24-cv-08891-LJC (N.D. Cal.), assigned to Magistrate Judge Lisa J. Cisneros. (Note a numbering wrinkle: several trackers — Patexia, the Ex Parte case page, and the caption in your prompt — render it as 5:24-cv-08891, reflecting the case's later renumbering into the San Jose series. Both numbers refer to the same docket; see dockets.justia.com docket 440883 vs. Patexia summary.)

Docket entries visible in public mirrors (Justia, UniCourt, RPX) run only through mid-December 2024:

One further docket reference exists in the wild: a filing in another case cites "CyboEnergy, Inc. v. Duracell Power Ctr., LLC, No. 24-cv-08891-LJC, ECF No. 10 (N.D. Cal. Dec. 12, 2024)" (CourtListener RECAP PDF). ECF No. 10 (Dec. 12, 2024) is consistent in timing and content with the Ramey firm's pro hac vice application — the sanctions order in Koji v. Renesas specifically describes a pro hac vice application filed 12/12/24 in the Duracell case by the Ramey firm (see below). That is a plaintiff-side filing.

There is no answer, no Rule 12 motion, no notice of appearance, no corporate disclosure statement, and no IPR- or stay-related filing by Duracell anywhere in the accessible record.

Termination

• Patexia lists a termination date of March 13, 2025, status "Dismissed – Voluntarily." (Patexia)
• Ex Parte's PACER-sourced page lists the case as "Status: Closed." (Ex Parte)

That date coincides exactly with the scheduled 3/13/2025 Initial Case Management Conference, a common point for a plaintiff to dismiss a case in which the defendant has not answered. I was not able to retrieve the text of the dismissal notice itself (e.g., whether it was Rule 41(a)(1)(A)(i) without prejudice), so treat the "voluntarily dismissed" characterization as well-sourced but the mechanics as unconfirmed. Notably, the Justia docket was "last retrieved on December 12, 2024," so it does not reflect the dismissal at all.

Why there is no defense counsel to name

The sequence is the explanation: complaint filed 12/10/2024 → summons issued 12/11/2024 → case dismissed ~3/13/2025. If service was effected, Duracell's responsive deadline would have fallen close to or after that date; if service was not perfected, no appearance would ever have been required. Either way, defense counsel never appeared of record, so the question "who is lead counsel / local counsel / of counsel for the defendant" has no docket-supported answer. I found no law firm announcement, Law360 or Reuters Legal coverage, or firm-website biography claiming representation of Duracell Power Center in this matter.

Context: the plaintiff-side counsel (for completeness)

Because you asked me to build on prior sections rather than repeat them, I'll keep this brief — but it is relevant that the only attorneys of record in this case are plaintiff-side, and this case has become a footnote in a sanctions proceeding:

• Jennifer L. Ishimoto (SBN 211845), Banie & Ishimoto LLP, 2100 Geng Road, Suite 210, Palo Alto, CA 94303 — signed the complaint and appears as plaintiff's attorney of record; the firm functions as local counsel. (complaint PDF)
• William P. Ramey III (and, per related Ramey filings, Susan S.Q. Kalra and Jeffrey E. Kubiak), Ramey LLP, Houston, TX — lead/plaintiff's counsel; the firm publicly claimed the filing in a December 2024 client alert (Ramey LLP).
• Important caveat for anyone relying on this docket: in its March 26, 2025 sanctions order in Koji v. Renesas Electronics Corp., No. 3:24-cv-03089-PHK (N.D. Cal.), the court listed CyboEnergy v. Duracell Power Center among 56 N.D. Cal. cases in which Mr. Ramey appeared while often not seeking pro hac vice admission, describing this case as "(attorney to be noticed)" and noting a pro hac vice application filed 12/12/24 averring "0" prior admissions in the preceding twelve months. (sanctions order via Reuters Legal; Supreme Court addendum) This is context about plaintiff's side only and says nothing about the defendant.

Verification steps I'd recommend before you rely on "no defense counsel"

I could not query PACER directly, and the free mirrors are stale (all last updated ~12/12/2024, with only aggregator-level data for the March 2025 termination). To close this out definitively:

1. Pull the full PACER docket for N.D. Cal. 3:24-cv-08891-LJC (and check the 5:24-cv-08891 series in case the renumbering created a separate docket record) and confirm whether any ECF entry after No. 7 bears a Duracell-side filer.
2. Check ECF Nos. 8–12 (mid-December 2024) for the Ramey pro hac vice papers and any order on them; and the final dismissal entry for the Rule 41 basis.
3. Confirm whether a proof of service was ever filed — that determines whether Duracell was even obligated to respond.
4. If you need the identity of the entity's litigation counsel for other matters (as opposed to this docket), the reliable route is the Delaware/state registration agent and Berkshire Hathaway-owned Duracell's outside-counsel roster, not this case file — but that would be a different question from "counsel of record here," and I have no sourced basis to name anyone.

Net: as of the accessible record, Duracell Power Center made no appearance and has no counsel of record in this case; the case was voluntarily dismissed on or about March 13, 2025.