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Run your analysis now →https://www.patsnap.com/resources/blog/rd-blog/battery-management-and-state-estimation-patent-landscape/ · Patsnap · data cut-off 2026-07-31 · downloaded from the live page
Patent Landscape · Battery Management & State EstimationBattery Management and State Estimation Patents
- Filing has cooled since its 2022 peak. 255 families published that year against 38 so far in the most recent year — though publication lag means the last year or two will always look thinner than they end up being.
- Three IPC subclasses carry almost the whole field. H02J, H01M and G01R each cover more than half of the 2,512 families, meaning power-electronics, cell-chemistry and measurement claims overlap on most filings rather than sitting in separate silos.
- Momentum is fading even among the most active filers. The assignee with the highest recent output is still down 70% year-on-year, and several others that built large portfolios show zero filings in the latest year.
2,512
Published Records
38%
Top-5 Share of All Records
-16%
Filing Growth 2021→2024
US
Leading Jurisdiction
Filing growth compares 2021 (247 records) with 2024 (208) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field. Top-5 share is the combined record count of the five largest assignees divided by all 2,512 records in scope (CR5), not by the ranked leaders only.
Published byPatsnap Research··8 min readSourced from Patsnap Eureka
Overview
What this landscape covers
This dataset tracks patent families claiming battery management systems and state-of-charge or state-of-health estimation methods, filtered to filings that name a specific estimation or balancing technique — Kalman filter, cell balancing, equivalent circuit model, impedance spectroscopy or aging prediction — inside classification codes covering power supply circuits (H02J7), electrical measurement (G01R31) and batteries or cells (H01M10). It spans 2,512 published families filed between 2015 and mid-2026.
The scope deliberately excludes battery chemistry claims that make no reference to management or estimation, and excludes general power-electronics filings that do not touch a battery. What remains is the control and diagnostics layer that sits between a cell and the system using it — the layer every EV, grid-storage and consumer-electronics battery pack needs regardless of chemistry.
Filing activity, 2017–2026
Source: Patsnap Eureka. Assignee ranking and totals. Derived from a Patsnap search on Battery Management and State Estimation covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
The data
Filing trend and technology composition
Two views of the same 2,512 families: how filing volume has moved year over year, and which classification codes those filings actually sit under.
A field that has already passed its filing peak
Annual filings rose from 99 in 2017 to a peak of 255 in 2022, then declined toward 38 in the most recent year. Because publication typically lags filing by around 18 months, the last one to two years understate true activity — but the shape of the decline from the 2022 midpoint is consistent enough to read as a genuine cooling rather than a reporting artefact.
Power, cell and measurement codes dominate
H02J (power supply and grid systems), H01M (batteries and cells) and G01R (electric and magnetic measurement) each appear in more than half of all families, confirming that most battery management filings are cross-disciplinary by construction — a claim naming a Kalman filter for SOC estimation routinely touches all three codes at once. B60L (EV propulsion) appears in roughly a quarter of families, marking the EV-specific subset of the field; G06N (AI-based computing) appears in only 64 families, suggesting machine-learning approaches to state estimation are still a minority claim style rather than the default.
Shares are the percentage of the 2,512 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Source: Patsnap Eureka. Filing trend and technology composition. Derived from a Patsnap search on Battery Management and State Estimation covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.
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Most-cited prior art and a recent representative filing
Representative recent filing
Battery Management System, Battery Pack, Electric Vehicle and Battery Management Method
LG ENERGY SOLUTION, LTD.
The filing describes a battery management system that runs two Kalman filters in parallel — one built on an equivalent circuit model and an SOC-open circuit voltage curve, the other on a constant current charge/discharge map — to produce a first estimated state of charge from sensed terminal voltage and current. It is a 2026 filing from LG Energy Solution, illustrating that dual-filter SOC estimation architectures remain an active claim style even as overall filing volume declines.Abstract condensed from the published filing; see the linked record for full claim language.
Highest-cited records in the corpus
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US9197079B2 | System and method for tracking and archiving battery performance data | 832 |
| 2 | US9099877B2 | Battery management system for control of lithium power cells | 824 |
| 3 | US20200164763A1 | Predictive model for estimating battery states | 379 |
| 4 | US20090104510A1 | Lithium rechargeable cell with reference electrode for state of health monitoring | 198 |
| 5 | US20120105001A1 | Systems and methods for battery management | 190 |
| 6 | US20130271072A1 | Wireless Battery Area Network For A Smart Battery Management System | 175 |
| 7 | US20080211459A1 | Battery management system and driving method thereof | 175 |
| 8 | US20160261127A1 | Method and system for battery management | 171 |
| 9 | US20120301747A1 | Battery pack | 171 |
| 10 | US20100052615A1 | Battery management system | 162 |
Citation counts accumulate over time and favour older filings; treat this table as a map of foundational prior art, not of current commercial importance.
Each row carries its publication number; clicking a row searches Eureka by that number.
Source: Patsnap Eureka. Citation counts and representative records. Derived from a Patsnap search on Battery Management and State Estimation covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
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What the numbers say about the field
Three patterns stand out once filing volume, classification spread and citation concentration are read together.
Filing trajectory
255 → 38
peak year to latest year
The field has already crested
Filings peaked at 255 in 2022 and have declined every year since toward 38 in the most recent (partial) year. Combined with publication lag, the honest read is a plateau-to-decline pattern rather than continued growth — new entrants are filing into a space with an established prior-art base rather than a rapidly expanding one.
Filing trend, 2017–2026
Classification overlap
1,409 / 1,328 / 1,319
H02J / H01M / G01R record counts
Claims routinely straddle three subclasses
The near-identical scale of H02J, H01M and G01R counts shows that a typical battery management claim is not filed in one classification silo — it combines power-circuit, cell-chemistry and measurement elements in a single family, which raises the bar for a clean freedom-to-operate search.
IPC composition
Citation concentration
832 & 824 citations
top two most-cited records
Foundational art sits with a small number of early filings
The two most-cited records in the corpus carry citation counts well ahead of the rest of the table, meaning the field's foundational architecture — tracking and archiving battery performance data, lithium cell control systems — was staked out early and cited widely since. Newer filings build claims around, not through, that art.
Most-cited records
Regional filing split
832 US, 514 EP, 297 CN
top receiving offices
US and European offices lead, China and India follow
The United States receives the largest single share of filings, with Europe close behind and China, India, WIPO and South Korea forming a second tier. A filer targeting only one major office risks missing prior art that entered through a different route entirely.
Receiving offices
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Looking for what nobody has claimed yet?
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to battery management and state estimation, with the prior art for and against each one.
Source: Patsnap Eureka. Co-assignee relationships and derived observations. Derived from a Patsnap search on Battery Management and State Estimation covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
Players
Who is filing, and who has stopped
The assignee ranking shows concentration among a handful of established filers, but recent-year momentum tells a different story: even the most active named assignee is filing far less than it once did, and several large portfolio holders show no filings at all in the latest year.
Momentum leader (declining)
6 filings, -70% YoY
latest-year filings, LG Energy Solution
Even the top filer is pulling back
LG Energy Solution shows the highest latest-year filing count in the momentum data, at 6 — but that is down 70% year-on-year, consistent with the broader decline from the 2022 peak rather than an exception to it.
Recent-year momentum
Zero-filing incumbents
0 in latest year
Samsung SDI, LG Chem, Bosch, CATL, Johnson Controls
Large historical filers have gone quiet
Several assignees with substantial cumulative portfolios — including Samsung SDI, LG Chem, Bosch, CATL and Johnson Controls — recorded zero filings in the most recent year in this dataset. That does not mean these firms have exited battery management; it more likely reflects filing timed to product cycles, or publication lag masking work already underway.
Recent-year momentum
Co-filing structure
10 co-assignee pairs
strongest pair: 28 shared families
Collaboration is concentrated in a few pairings
Only ten co-assignee pairs appear in the dataset, and the strongest — Samsung SDI with Bosch — accounts for 28 shared families, well ahead of the next pairings. Co-filing here looks like a small number of deliberate joint-development relationships rather than a broad industry norm.
Co-assignee pairs
Recent-year filing momentum by assignee
| Assignee | Recent year | YoY |
|---|---|---|
| LG Energy Solution | 6 | -70% |
| Samsung SDI | 0 | -100% |
| LG Chem | 0 | — |
| Robert Bosch GmbH | 0 | — |
| Contemporary Amperex Technology Co., Ltd. (CATL) | 0 | — |
| Johnson Controls Technology Company | 0 | — |
| Zoll Circulation, Inc. | 0 | — |
| Infineon Energy, Inc. | 0 | — |
Source: Patsnap Eureka. Assignee-level momentum. Derived from a Patsnap search on Battery Management and State Estimation covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
What's next
Where to take this
The landscape data points to specific next checks rather than a single conclusion.
Run a freedom-to-operate check against the highest-cited records
The two most-cited families in this corpus carry citation counts far above the rest of the table and likely anchor claim language that later filings work around. Any new SOC or SOH estimation filing should be checked against these before drafting.
Explore prior art in EurekaWatch whether the 2022 peak was cyclical or structural
Filing has declined for several years running, but publication lag means the most recent two years are undercounted. A follow-up pull in twelve months will show whether the decline continues or corrects.
Track filing trends in EurekaTest the under-claimed branches for a first-filer advantage
AI-based estimation and impedance-spectroscopy-based aging diagnosis show thinner density relative to the core equivalent-circuit-model claim space, which may leave room for a narrowly drafted first claim.
Map white space in EurekaSource: Patsnap Eureka. Forward-looking reading of the same dataset. Derived from a Patsnap search on Battery Management and State Estimation covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
FAQ
Common questions about this landscape
The dataset shows filing concentrated among a small group of large battery and automotive suppliers, with LG Energy Solution showing the most recent-year activity even as that activity declines year-on-year. Several other major historical filers, including Samsung SDI, LG Chem, Bosch, CATL and Johnson Controls, hold large cumulative portfolios but show no filings in the latest year of this dataset. This pattern suggests leadership in this field is defined more by accumulated portfolio depth than by current filing pace, so a ranking based purely on total family count will understate how active a given company is right now.
Filing activity peaked at 255 families in 2022 and has declined every year since, reaching 38 in the most recent partial year. Because patent publication typically lags filing by around 18 months, the most recent one to two years will always look thinner than they eventually turn out to be, so the true 2025-2026 figures are likely higher than currently shown. Even accounting for that lag, the multi-year decline from the 2022 midpoint points to a field that has moved past its filing peak rather than one still accelerating.
The core classification codes are H02J (power supply and grid systems), H01M (batteries, cells and fuel cells) and G01R (electric and magnetic measurement), each appearing in more than half of the 2,512 families in this dataset. B60L, covering electric vehicle propulsion, appears in roughly a quarter of families and marks the EV-specific subset. Smaller codes such as G06N (AI-based computing) and H02H (protective circuits) appear far less often, indicating those are still niche claim styles rather than mainstream ones.
This 2026 filing from LG Energy Solution claims a battery management system that runs two Kalman filters in parallel — one anchored to an equivalent circuit model and an SOC-open circuit voltage curve, the other to a constant current charge/discharge map — combining their outputs into a first estimated state of charge from sensed terminal voltage and current. Anyone designing a dual-filter or multi-model SOC estimation architecture around similar inputs should review this filing's specific claim scope before finalising an approach. It does not block single-filter equivalent circuit model estimation on its own, since that architecture has extensive earlier prior art in this same corpus.
The classification data shows G06N (AI-based computing) appearing in only 64 of 2,512 families, meaning machine-learning-driven SOC or SOH estimation is comparatively under-claimed relative to the dominant equivalent-circuit-model and Kalman-filter approaches. Impedance-spectroscopy-based aging diagnosis and protective-circuit integration (H02H) also show thinner filing density than the core measurement and power-circuit codes. These are not guarantees of a clean filing path, but they are areas where the claim space is less crowded and worth a targeted prior-art search before drafting.
Answers are grounded in the same dataset. Derived from a Patsnap search on Battery Management and State Estimation covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
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Disclaimer. This page is generated from Patsnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company's registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.