Patent disputes in ESS are on the rise: Here’s how developers can prepare

Where patent risks arise in stationary ESS

Stationary ESS disputes often revolve around systems rather than just cells. Even when a complaint is framed around “battery technology,” the friction points typically sit at the seams, where different subsystems meet and where integration choices become distinctive.

The recurring high‑risk categories for stationary ESS include:

• Power conversion systems (PCS) and power management: inverter topology, DC‑DC conversion, switching strategies, grid‑support functionality, black‑start, islanding detection, and related firmware‑controlled behavior.

• Thermal management and safety architecture: enclosure design, coolant routing, venting, fire detection and suppression integration, safety interlocks, and temperature sensing/monitoring.

• Battery management systems (BMS) and controls: state estimation, balancing, fault detection, protection logic, data pipelines, and remote update pathways.

• Mechanical packaging and module architecture: rack systems, busbar configurations, connector interfaces, serviceability design, and assembly methods.

• System integration features: how PCS, BMS, EMS, and site controllers communicate; which data is measured where; and which control decisions occur at which layer.

This matters because system claims are easier to assert broadly (they can read on multiple implementations), and integration decisions are often made under schedule pressure—exactly when documentation and IP screening are most likely to be abbreviated.

Scale-up creates predictable patent flashpoints

Most storage companies expect legal activity after commercial success. In stationary ESS, patent disputes often appear before the first truly scaled deployments—because scale‑up requires actions that expose the company to scrutiny for the following reasons:

Visibility and reverse engineering increase: When a product is deployed at scale, competitors can more readily infer its architecture from publicly available project information, interconnection requirements, teardown photos, grid services behaviour, and service documentation. Even without physical access to hardware, performance and interface behaviour can be revealing.

Supply chains change: Scale-up triggers second-source efforts, cost-down component substitutions, and contract manufacturing transitions. Those changes can unintentionally introduce components or configurations that are covered by existing patents.

Integration becomes the differentiator: At the pilot level, many products look alike. At the grid-scale, differentiation often comes from control logic, safety features, and integration efficiencies. These are precisely the areas where patent portfolios are frequently built.

If you wait until a demand letter arrives, you are reacting at the worst moment, when design changes are expensive, procurement is locked, and deployment contracts may create exposure.

What to evaluate before scaling ESS manufacture

A ‘pre‑scale IP check’ does not need to be a months‑long freedom‑to‑operate effort to be useful. The key is to target the few architectural decisions that create the most exposure and to document them in a way that preserves options.

Here is a streamlined approach that works well in practice:

Step 1: Identify the ‘architectural anchors’

Pick the core features that define the ESS design—especially integration choices that would be difficult to change later (e.g., cooling approach, enclosure layout, sensing strategy, PCS/BMS interface, safety interlock architecture).

Step 2: Perform a focused landscape scan

Look for patents held by direct competitors and by well‑known patent holders in power electronics, battery safety, and BMS. The goal is not perfection. It is to find obvious overlaps early enough to adjust. Another good strategy is to look at patents asserted against other players in the industry, such as competitors and entities along the supply chain.

Step 3: Document design intent and alternatives

Many disputes turn on whether a feature is essential or incidental. Maintaining short internal notes on why your team chose an approach—and what alternatives were considered—can meaningfully reduce future disruption.

Step 4: Align engineering, sourcing, and legal on ‘change control’

One easily avoidable risk is late substitutions by suppliers without a clear internal path to evaluate IP impact. Your change‑control process should include an “IP checkpoint” for high‑risk substitutions (PCS components, thermal subsystems, safety systems, communications modules, control firmware changes).

Step 5: Build an ‘evidence package’ before you need it

If a dispute arises, outside counsel will need to understand how the system works quickly. A well-organised technical package (block diagrams, interface control documents, high‑level control logic description) shortens response time and reduces engineering distractions.

This is not bureaucracy. It is a scale‑up discipline and is no different than quality systems or safety case documentation.

Imported components and licensed technologies are where hidden exposure lives

Stationary ESS is a global manufacturing story. Cells, power semiconductors, enclosures, sensors, connectors, and control boards often cross borders multiple times before final integration. That reality creates two categories of risk that often surprise companies.

Import-linked disputes

When key components or finished systems are imported, disputes can move fast and become operationally disruptive. Even outside specialised venues, supply chains are vulnerable to the mere prospect of an import‑focused complaint or a request for emergency relief, because procurement, logistics, and customers demand certainty.

What to do now:

• Map your supply chain to identify which components could trigger ‘importation’ pressure.
• Identify second‑source options in advance for the most sensitive components.
• Keep records showing where key design and engineering work occurred; these details can matter in various forums.

Licensed technologies and ‘stacked rights’

ESS businesses frequently incorporate licensed technologies—software, control algorithms, comms stacks, sensor packages, safety modules, or even reference designs. The risk is not simply whether you have a license; it is whether the license scope is aligned with how the product is deployed and sold.

Common traps include:

• A license that covers development but not commercial deployment at scale
• Field‑of‑use limitations (e.g., stationary vs. mobility; grid‑connected vs. behind‑the‑meter)
• Restrictions on sublicensing to integrators or EPCs
• Misalignment between your customer contracts and your upstream license obligations

What to do now:

• Before scaling, audit licenses tied to essential subsystems (BMS software, PCS firmware modules, safety tech).
• Confirm the license scope matches target markets and deployment models.
• Ensure contract terms with customers align with your upstream obligations.

Redesign strategies to reduce infringement risk without delaying deployments

Redesign is often framed as an all‑or‑nothing exercise: either accept the asserted risk or rebuild the product.

In practice, effective redesign is typically surgical, especially in ESS, where many patents focus on particular combinations of features or specific control behaviours.

A redesign strategy can work when:

• the asserted claim depends on a specific sensing approach, control decision, sequence, or interface architecture
• alternative designs are feasible without disrupting safety certifications or interconnection requirements
• changes can be introduced in a controlled ‘revision’ while maintaining backward compatibility

Redesign is less viable when:

• the claim is truly broad and reads on nearly any compliant implementation
• the disputed feature is deeply tied to certification, safety case, or interconnection agreements
• the product is locked by procurement realities and customer commitments

A practical redesign playbook for ESS:

1. Identify which claim elements actually matter (often only one or two drive real risk).
2. Brainstorm alternatives with engineering early—not after a complaint is filed.
3. Prioritise changes that preserve the schedule: firmware adjustments, control‑logic modifications, sensor placement changes, interface remapping, or mechanical rerouting that avoids core architecture changes.
4. Validate the redesign against performance and compliance constraints before it is treated as an escape route.

What ESS companies should expect, moving forward

Looking ahead, the stationary ESS sector is likely to see more disputes driven by five dynamics:

1. Crowded competitive field and margin pressure → IP becomes a competitive lever.
2. Convergence of technologies (PCS, controls, safety, thermal management) → more overlap and more assertion opportunities.
3. Global sourcing complexity → more supply‑chain pressure points.
4. Increased standardisation and interoperability → patents asserted around interfaces and system behaviours.
5. Rising importance of safety and reliability features → more patents and more scrutiny around protective architectures.

The practical implication is not that every company will be sued; it is that every company should be prepared to respond quickly, with minimal disruption, and with a plan that integrates legal strategy into engineering and operational realities.

Treat ESS as a scale-up discipline, not a surprise event

Stationary ESS companies are building critical infrastructure under intense time pressure. Patent disputes are increasingly part of that landscape—especially during scale‑up, integration, and global sourcing transitions.

The companies that navigate this well do not necessarily spend more on legal work. They build small, repeatable habits: targeted pre‑scale checks on high‑risk subsystems, disciplined change control for component substitutions, clean documentation of design intent, and a realistic redesign plan that preserves deployment momentum.

In a market where execution speed and reliability are competitive advantages, reducing IP‑driven disruption is itself a form of operational excellence.

About the Author

Isaku Begert is an intellectual property litigation attorney at Marshall, Gerstein & Borun LLP, a US-headquartered provider of IP advice and legal services.

DISCLAIMER: The information contained in this article is for informational purposes only and is not legal advice or a substitute for obtaining legal advice from an attorney. Views expressed are those of the author and are not to be attributed to Marshall, Gerstein & Borun LLP or any of its former, present, or future clients.