There’s drama in the niche world of battery-powered induction stoves. The two leading companies in the category — Copper and Impulse Labs — are now suing each other, with Copper accusing Impulse of patent infringement and Impulse hitting back with allegations of false advertising.
The dispute formally began in early April, when Copper filed suit against Impulse for willful patent infringement, alleging that its rival not only copied Copper’s proprietary battery-integration technology, but did so knowingly. Both companies sell high-end induction stoves with built-in batteries, a design that allows them to plug directly into standard 120-volt household outlets — the same kind you would use to charge a phone or operate a toaster — rather than the less common 240-volt outlets that electric and induction stoves typically require. That helps customers avoid expensive electrical upgrades that could add thousands to the installation process while also equipping them with a stove that can run off battery power during a power outage.
According to Copper’s suit, the company started developing its own battery integration tech in 2019. It went on to file its first provisional patent application in March 2021, before formally incorporating as a company the following year. By January 2025, the company had secured three patents for various aspects of its battery-stove integration, and has raised $39 million in venture funding to date.
Impulse, which was founded in 2021, has raised about $25 million, though it has yet to secure patents for the core battery-integrated system at the heart of its product. That’s not for lack of trying — while it’s unclear whether the company was familiar with Copper’s tech when it began developing its product, the U.S. Patent and Trademark Office has repeatedly rejected Impulse’s patent applications for its integrated battery-and-power-management system, citing Copper’s existing protections. Impulse has since amended those applications and says the USPTO is preparing to issue patents related to the core system, adding to the company’s existing patents covering its magnetic control knobs and modular battery design.
That’s central to Copper’s case. Because the patent office and Impulse reference Copper’s patents in their exchange, Copper says this proves that Impulse was fully aware of its intellectual property, therefore making any infringement “willful.” That designation would substantially increase whatever damages Copper might seek to extract if the company can prove it in court.
When all this came out back in April, Impulse provided a fiery statement to Fast Company, saying “such lawsuits are a common tactic taken by companies that are losing in the marketplace,” referring to the suit as a “PR stunt.” Then last week, Impulse fired back with some claims of its own.
First, it denied Copper’s allegations, raising several standard defenses common to this type of litigation, such as the claim that Copper’s patents are invalid and should not have been issued in the first place. Impulse hasn’t yet provided much detail here — those arguments will likely emerge as the case progresses. So far its counterclaims alleging false advertising are what really pack a punch.
Firstly, Impulse alleges that Copper makes misleading statements about its safety certifications. In its countersuit, Impulse states that it spent “approximately two years and in excess of a million dollars” obtaining Underwriters Laboratories certification for its tech, covering both household electric ranges as well as rechargeable stationary batteries. Yet Copper says on its website that with regards to electric ranges, “UL does not yet certify battery-integrated appliances” — a claim Impulse says can’t possibly be true, given that it went through the process and received certification itself.
Impulse goes on to say that “many states and municipalities have issued laws that require products, including battery-powered electric cooking appliances, to comply with UL standards,” thereby arguing that Copper’s framing misleads consumers into thinking certification isn’t available or necessary. It also contends that while Copper advertises its batteries are UL certified, they actually only hold “recognized component” status — a conditional designation that Impulse argues is incomplete unless the full stove itself is UL-certified — which, as discussed, it is not.
In a statement, Impulse told me, “We believe consumers deserve accurate information when making decisions about the products they bring into their homes. That’s why we’ve brought counterclaims against Copper’s advertising practices which we believe have been deceptive. We’re proud that the Impulse Cooktop is certified to UL 858, the safety standard for household electric ranges, and to UL 1973, the standard for the battery system inside it.”
There’s also the question of tax credit eligibility. Multifamily property owners purchasing stoves with at least 5 kilowatt-hours of integrated battery storage could, at least in principle, qualify for the federal Clean Electricity Investment Credit under Section 48E of the U.S. tax code. This gives buyers a 30% credit for a range of technologies, including energy storage, a category these stoves technically fall into. In theory, such systems could even serve as a grid resource, shifting electricity use away from peak periods or charging when renewable power is abundant.
Copper says on its website that its stoves are eligible for 48E, but Impulse alleges that’s false, pointing to the “material assistance” restrictions that President Trump’s One Big Beautiful Bill Act introduced, which require eligible projects to avoid significant input from countries designated “foreign entities of concern” such as China. Impulse argues that Copper doesn’t meet this standard, asserting that key components of its system — including the battery and housing —- are largely made in China. Impulse, on the other hand, does not claim eligibility for 48E; regardless of where the company gets its components, its smaller, 3-kilowatt-hour battery would prevent it from qualifying anyway.
In an interview, Copper co-founder Weldon Kennedy categorically denied that his company has “been misleading in any way whatsoever,” whether on safety standards, third-party certifications, or tax credit eligibility. In a subsequent statement, the company added, “Copper builds appliances that enable access to clean energy and is working to bring this technology to the market with major appliance makers. We are also taking steps to ensure that this technology is adopted responsibly and transparently. To that end, we cannot support the unlicensed use of Copper’s IP, and we have taken steps to protect it and ensure the progress of the category.”
Neither Copper nor Impulse discloses customer counts, unit sales, or revenue figures. Copper, however, has landed one high-profile commercial deal: The New York Power Authority and New York City Housing Authority have awarded it a $32 million, seven-year contract to provide 10,000 battery-equipped induction stoves to apartments across the city, assuming an initial 100 unit pilot goes according to plan.
It’s unclear whether the competing lawsuits will affect this deal. But the Power Authority’s press release on the partnership does suggest confidence in Copper’s safety certification strategy, stating that the company “will work with industry testing and safety standards organizations, such as Underwriter Laboratories, to achieve certification for novel technologies prior to the pilot phase.”
The climate tech world will be watching closely for Copper’s formal response to Impulse’s counterclaim. Both companies have demanded a jury trial, though any courtroom showdown must come after a discovery process that could stretch on for many months. In the interim however, the litigation adds a new complication — and distraction — for two startups attempting to establish an entirely new appliance category. And whoever comes out on top could ultimately determine who gets to shape the market itself.
Editor’s note: This story has been updated to correct Impulse Labs’ patent status.
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