Lead-Acid Battery Patents: Who Leads, Where Filings Are Flat 2026
- Filing has already peaked. 2018 was the high-water mark at 50 records; by the midpoint year 2022 filings had dropped to 18, and the trend has stayed flat to declining since.
- The top of the field is concentrated. Five assignees account for 51.1% of all 462 records in scope, and the top ten reach 59.3% — a leader well ahead of the field plus a long tail of single- and low-filing entrants.
- Almost every record sits in one class. 99.8% of records carry an H01M battery/cell classification, but smaller clusters in power supply systems, polymer separators, alloys and EV propulsion mark where the differentiated claim activity actually is.
What this dataset covers
This landscape covers 462 published records filed between 2015 and mid-2026 that combine lead-acid battery terminology — VRLA, AGM, sulfation, grid corrosion, deep-cycle life, start-stop duty and lead recycling — with IPC classes covering batteries and cells (H01M10, H01M4) and lead metallurgy (C22B13). The scope is deliberately narrow: it targets the durability and recycling-loop problems that keep lead-acid relevant against newer chemistries, not general battery filings.
Filing offices skew toward the United States and Europe, with meaningful volume through WIPO's PCT route and a smaller but present cluster in India, China and Japan. That spread points to a technology still being defended across multiple jurisdictions rather than one filed defensively in a single home market.
Filing trend and technology composition
Two views of the same 462 records: how filing volume has moved year over year, and how those records distribute across IPC subclasses. Because a single record can carry several classes, the class shares below add up to more than 100% of the record total.
Filing trend, 2017–2026
Volume ran from 29 records in 2017 to a peak of 50 in 2018, then eased through the 2022 midpoint at 18 and down to 1 in the most recent, still-partial year. Publication lags filing by roughly 18 months, so the last one to two years will always look thinner than they eventually turn out to be — but the multi-year decline from the 2018 peak predates that lag effect.
IPC subclass distribution
H01M (batteries, cells and fuel cells) covers 99.8% of the 462 records, confirming the search scope. Below that, H02J (power supply and grid systems) at 8.4%, C08L (polymer compositions) at 3.2%, G01R (electric and magnetic measurement) at 3.0%, C22C (alloys) at 2.4%, B60L (EV propulsion) at 2.2% and C08K (polymer additives) at 1.3% mark the secondary claim territories — separator chemistry, alloy grid design, monitoring electronics and vehicle integration.
Shares are the percentage of the 462 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Lead-Acid Battery Technology with Eureka
This page is one run against one query. Ask Eureka your own question about lead-acid battery technology and every answer comes back with the patent numbers behind it.
Try EurekaMost-cited records in the corpus
US6106968A — Smart valve regulated lead acid battery with embedded electronic monitoring and fluid fill system
For use with a valve regulated lead acid (VRLA) battery, a fluid fill system and a method of maintaining fill fluid in a VRLA battery. In one embodiment, the system includes a fluid determination circuit, associated with the battery, that determines a quantity of fill fluid in the VRLA battery, and a controller, coupled to the fluid determination circuit, that introduces replacement fill fluid based on the quantity to replace fluid lost from the battery. The fluid determination circuit comprises sensors that measure temperature and pressure associated with the battery, and the state of a fluid release valve on the battery.Filed by Lucent Technologies, granted 2000-08-22 — one of the most-cited records in this corpus and a foundational claim on automated fluid management in VRLA batteries.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20120070713A1 | Separators, batteries, systems, and methods for idle start stop vehicles | 107 |
| 2 | JP2008243487A | Lead acid battery | 80 |
| 3 | US5063341A | Lead acid battery rejuvenator and charger | 80 |
| 4 | US20090015193A1 | Power Supply Device, Control Method of Power Supply Device, and Motor Vehicle Equipped with Power Supply Devi… | 73 |
| 5 | US6106968A | Smart valve regulated lead acid battery with embedded electronic monitoring and fluid fill system | 58 |
| 6 | US20120070728A1 | Compositions and delivery systems with leachable metal ions | 49 |
| 7 | US6755874B2 | Plate making process for lead acid battery | 49 |
| 8 | US20170098810A1 | Functionalized lead acid battery separators, improved lead acid batteries, and related methods | 41 |
| 9 | US6649306B2 | Alloy for thin positive grid for lead acid batteries and method for manufacture of grid | 41 |
| 10 | US20180151872A1 | Graphene-protected lead acid batteries | 40 |
Citation counts reflect influence within this searched corpus and favour older filings; they are not a measure of current commercial importance.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Browse MCP servers →What the numbers mean for filing strategy
Read together, the concentration figures, the trend line and the IPC spread describe a mature claim space with a declining filing rate at the core and pockets of active differentiation at the edges.
A leader well ahead, then a steep drop
The leading assignee alone holds 177 records. The top five combined reach 51.1% of the 462 records in scope, and the top ten reach 59.3% — concentration that leaves the remaining 90 ranked entities filing in single digits or low double digits each.
Filing has passed its peak
Volume peaked at 50 records in 2018 and has trended down since, sitting at 18 by the 2022 midpoint. New filing into the core lead-acid claim space is not accelerating, which is consistent with a chemistry facing competitive pressure from newer battery types rather than one still expanding its own claim territory.
Core class saturated, edges more open
Almost every record in scope sits in H01M, confirming this is a lead-acid-specific corpus. The smaller shares in H02J, C08L, G01R, C22C and B60L mark where cross-disciplinary claims — grid electronics, separator polymers, alloy metallurgy, EV integration — carry comparatively less filing density.
Filing spread across major offices
The United States leads receiving offices with 155 filings, followed by the EPO at 101 and WIPO's PCT route at 56. India, China and Japan each carry smaller but non-trivial volumes, indicating protection sought across multiple markets rather than concentrated in one jurisdiction.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to lead-acid battery technology, with the prior art for and against each one.
| Assignee | Co-assignee | Shared families |
|---|---|---|
| CPS Technology Holdings LLC | CLARIOS GERMANY GMBH & CO KGAA | 4 |
| CPS Technology Holdings LLC | Clarios Germany GmbH & Co. KGaA | 2 |
| Johnson Controls Technology Co | WYATT PERRY | 2 |
| Johnson Controls Technology Co | LOGANATHAN KAVI GEETHARANI | 2 |
| Johnson Controls Technology Co | JIANG JUNWEI | 2 |
| CPS Technology Holdings LLC | Johnson Controls Automotive Battery LLC | 1 |
| Johnson Controls Technology Co | WETZEL DENNIS A | 1 |
| Johnson Controls Technology Co | TELISKA MARGARET | 1 |
Ten co-assignee pairs appear in the corpus; the strongest links group corporate parents with their own subsidiaries and named inventors, a pattern typical of internal group filing rather than cross-company joint development.
Who holds the claim space, and where it's still open
The ranked leaders account for a majority of filings, but recent-year momentum for the largest names has dropped to zero — none of the top assignees checked show active filing in the latest year. That combination, a concentrated but stalled top tier, is what opens room at the edges.
One assignee well ahead of the field
The top-ranked assignee holds 177 of the 462 records in scope, far ahead of the fifth-place holder at 10 and tenth place at 7. That gap suggests a long-standing filer with a defensive portfolio built over years, not a recent surge.
Leaders have stopped filing, at least on paper
Every leading assignee reviewed for recent-year momentum shows zero filings in the latest year, with some recording a full year-on-year drop. Given the roughly 18-month publication lag, this understates true recent activity, but a multi-year pattern of decline from the 2018 peak was already visible before that lag effect.
Co-filing is mostly intra-group
The ten identified co-assignee pairs mostly link a parent company to its own subsidiary or a named inventor, rather than showing cross-company joint filings. That points to internal corporate restructuring in ownership records more than to collaborative R&D partnerships.
| Assignee | Recent year | YoY |
|---|---|---|
| Daramic LLC | 0 | -100% |
| CPS Technology Holdings LLC | 0 | -100% |
| Johnson Controls Technology Co | 0 | — |
| RSR Technologies Inc | 0 | — |
| Hollingsworth & Vose Company | 0 | — |
| Shin-Kobe Electric Machinery Co., Ltd. | 0 | — |
| Delphi Technologies LLC | 0 | — |
| Commissariat a l'Energie Atomique et aux Energies Alternatives | 0 | — |
Where to take this next
The dataset points to a field with a stalled core and open edges. The next step is usually narrower: checking a specific claim against the leader's portfolio, or scoping a filing in one of the under-claimed branches.
Check freedom to operate against the leader's portfolio
With one assignee holding 177 of 462 records, any new filing in core VRLA or AGM claim territory should be checked against that portfolio first, not against the field average.
Run a freedom-to-operate check in EurekaScope a claim in an under-claimed branch
Alloy metallurgy, separator polymer additives and embedded monitoring sit at low single-digit shares of the 462 records — worth a closer look before assuming the space is crowded.
Explore white space in EurekaTrack whether filing has actually stopped or just lags
Recent-year momentum shows zero filings from leading assignees, but publication lag of about 18 months means the true picture for the last one to two years is still forming.
Set up filing alerts in EurekaCommon questions about lead-acid battery patents
One assignee leads the ranked field with 177 of the 462 records in scope, well ahead of the fifth-ranked holder at 10 records and the tenth-ranked at 7. The top five assignees combined hold 51.1% of all records, and the top ten reach 59.3%. This is a concentrated field at the top, with a long tail of entities holding only one or a handful of filings each.
No. Filing peaked at 50 records in 2018, fell to 18 by the 2022 midpoint, and has continued to decline since, with only 1 record recorded in the most recent year. Because publication lags filing by roughly 18 months, the very last year or two will always look artificially thin, but the multi-year decline from the 2018 peak was already established before that lag effect kicks in.
The core H01M battery/cell classification covers 99.8% of the 462 records, meaning it is heavily claimed. Smaller clusters in polymer separator compositions, alloy metallurgy, embedded monitoring electronics and EV propulsion integration sit at low single-digit shares of the record total, which is where new, more specific claims are more likely to find open space than in the core cell chemistry itself.
The United States receives the most filings in this dataset at 155, followed by the European Patent Office at 101 and the WIPO PCT route at 56. India, China and Japan each carry smaller volumes. The spread across the US, Europe and the PCT system suggests companies are seeking protection in multiple major markets rather than filing defensively in a single jurisdiction.
US6106968A, granted to Lucent Technologies, claims a fluid fill system for valve-regulated lead-acid (VRLA) batteries that uses sensors to measure temperature, pressure and valve state, then automatically replaces lost fill fluid via a controller. It is one of the most-cited records in this corpus, meaning many later filings in embedded battery monitoring reference it. Anyone drafting claims around automated electrolyte or fluid management in VRLA batteries should review this patent's specific sensor-and-controller architecture before finalising claim language.
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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.