In January, a Finnish-Estonian startup proclaimed it had developed a truly solid state battery, a holy grail for the technology industry. Donut Labs’ cell wasn’t just solid state, however. It claimed it was made from cheap and easily available materials, would charge to full in a few minutes and last for hundreds of years. If real, such a device would change the face of the world, which is why plenty of people don’t think it is. And, as the company makes more effort to demonstrate it is telling the truth, the more holes people are finding to poke their fingers into. So, what the hell is going on with Donut Labs’ battery? After many weeks of research, I’m throwing my hands in the air, tired of the endless dog and pony show the company is putting on.

Solid state batteries

Conventional batteries have improved a lot in the last few decades but remain imperfect in many ways. Cells found in electronics and EVs commonly use liquid or gel polymer as an electrolyte. These electrolytes are the cause of thermal runaway, where the heat of a battery increases exponentially, and can become a primary cause of battery failure and fire. Plus, they’re pretty fussy, requiring a consistent temperature for peak performance and to be treated pretty delicately. It’s why the industry has raced to develop a solid state battery that eliminates the liquid or gel polymer.

Because of their higher energy density, solid state batteries should be lighter and smaller per watt than conventional batteries. These benefits would be enjoyed widely but are vital for an EV where weight and size dictate so much of how it operates. Solid state batteries are at far less risk of thermal runaway, and should work in a much wider temperature window. Now, we are already seeing plenty of semi-solid batteries coming into the market, with fully-solid cells expected in the near future. Chinese battery giant CATL told at the end of 2025 that its first small-scale production of solid state batteries is anticipated to begin in 2027. However, those first production runs are likely to be limited rather than global rollouts.

Donut Lab

Enter Donut Lab. The startup is a subsidiary of Finnish motorcycle maker Verge Motorcycles, famous for its . Verge says it has built the “world’s most powerful electric motor family,” and that it made “all the components needed to build an electric vehicle.” Verge’s motors have since been incorporated into recently announced Speedster EV.

At CES 2026, Donut Lab it had built the world’s “first full all-solid-state battery.” It said this wasn’t just a prototype, but was “ready to power up production vehicles now.” In a glossy promotional video, the company said it had solved the issues the whole industry had been working to solve for decades. There was nothing but upside, with none of the trade-offs its competitors had been forced to make while developing their own solid state batteries. And, it was ready to be incorporated into EVs starting today. Verge Motorcycles announced it would add the battery into its TS Pro, with shipments expected to begin Q1 2026.

Donut Labs’ battery

The company’s begins by saying the cell has an energy density of 400Wh per kilogram, roughly twice the density of the best lithium ion battery on the market. Right now, you should expect to get around 1,000 charge and discharge cycles out of any half-decent battery. Donut Labs is promising its cell will last for a whopping 100,000 cycles, even if you’re fast-charging the cell. The company promises users will be able to reach an 80 percent charge from zero in around five minutes, and get to full in under six. Donut said the cell offers a “clay-like” freedom of design, adapting to the specific needs of a specific product, rather than the other way around.

Naturally, pumping all of that power into such a small cell will mean it’ll need a lot of babying, right? Not according to Donut Lab, which says its battery will operate in temperatures as low as -30 degrees Celsius (-22 Fahrenheit) or as hot as 100 degrees Celsius (212 Fahrenheit). And, to top it off, it’s made from common, easily-available and cheap materials which are “geopolitically safe,” rather than from rare-earth minerals sometimes held by rival nations. All of that means the cell will be cheaper to produce than the equivalent lithium ion cell and, best of all, Donut said the battery is ready for scaled production.

A battery that promised some of these features would be world-changing; one offering all of them would be world-shattering. It would upend supply chains, shift the global balance of power, potentially eliminate reliance on so-called rare earth minerals and supercharge EV adoption. But Donut Lab offered no proof for its claims, no hint as to what its process was based upon, and no sign it had the manufacturing capacity to deliver on its promises. Naturally, a lot of people just didn’t believe what they were seeing and hearing, and called BS.

People are suspicious

Yang Hongqin, CEO of Chinese battery maker Svolt, was quoted by as saying “any person with even a basic understanding of the technology would think it’s a scam.” Finnish newspaper reported that CATL’s venture capital head Ulderico Ulissi described the matter as “clearly fake.” That comment prompted Donut CEO Marko Lehtimäki to respond on LinkedIn, saying that Ulissi would “regret the arrogance.” Tom Bötticher, CEO of battery startup Litona, posted on his belief Donut’s technology is actually tied to a company Donut invested in, Nordic Nano. Bötticher found a pitch deck, which is no longer available (but is here at the ) which described Nordic’s energy storage technology as a supercapacitor.

Some have pointed out that Lehtimäki has a track record of making strong claims about his products. On May 15, 2025, he announced an AI startup, ASILAB, and said in a similarly glossy launch video that his team had created a “synthetic counterpart” to the human brain. Its first product, ASINOID, Lehtimäki said, is a “dynamic self-developing organism designed to grow in capability and in consciousness.” The company said it would open up access to ASINOID, but I’ve been unable to find any evidence that any such access has been granted. ASILAB has not responded to our request for comment.

Similarly salty write-ups can be found in , , , and just about every Reddit, YCombinator and Hacker News thread discussing the technology.

I Donut Believe.com

In response to the minor social media backlash, Donut Labs went on the offensive. It launched the website promising a weekly drop of so-called evidence to support its claims. In a polished video introduction, Lehtimäki said the criticism comes from parties with vested interests, such as competitors. He addressed the above attack lines directly, saying people have been assembling theories from scraps of online data to create an untrue picture. He also denied claims the battery was a supercapacitor.

In the same video, Lehtimäki said the media has amplified “so-called experts” from the battery industry, taking their opinions at “face value.” Naturally, rival researchers who would stand to gain by taking down a potential challenger have a natural desire to rubbish Donut’s claims. But because many of them are credentialled experts in the field, their authority was elevated above his own.

Crucially, Lehtimäki said Donut didn’t publish validation tests at the time of announcement as it would have been similarly dismissed by those same biased voices. By holding the proof back, he said it forced Donut’s competitors to essentially show their hand, making it easier to refute them. To do so, Donut engaged VTT Finland, a research organization which offers to third VTT has conducted specific tests on cells supplied by Donut, the results of which the company has released piecemeal over several weeks.

It’s important to note that don’t make any statements which could be seen to support Donut’s claims. For instance, it says it was asked to “conduct independent charging performance tests on the energy storage devices supplied by the customer, which the customer identified as solid-state battery cells.”

The tests

Donut Lab published a test for five weeks, each one each one designed to show off one key feature of the battery. saw VTT fast charge a cell beyond the limit of a regular battery, after which it still had close to 100% of its charge available for use. In , VTT charged the cell to full, and then discharged it in high-temperature environments. Once that was done, the cell was charged again at a normal temperature, but researchers noted that the pouch lost vacuum. Donut Lab later said the vacuum loss was caused by the packaging materials not being able to withstand the temperature, rather than an issue with the battery itself.

A VTT spokesperson told me “during the final stage of manufacturing, all gases are removed from the cell, and the cell is sealed tightly under vacuum conditions. The cell feels firm. If the cell loses its vacuum, it usually becomes slightly soft and swollen.” Essentially, if a battery loses its vacuum, it means it’s started swelling, which is visible in the photos from the report. Swelling is fatal to a traditional lithium ion battery and, potentially, the device it’s connected to.

purported to disprove the idea that Donut was secretly selling a supercapacitor, so VTT charged the cell to full and let it sit idle for 10 days. At the end of that time, the charge level of the battery appeared to hold steady, with a small drop commonly seen in all batteries. Which appeared to confirm the cell was a battery, rather than a capacitor which may struggle to hold its charge over longer periods of time. Test Four was conducted by Donut Lab itself, taking a prototype of its battery in a Verge motorcycle to a fast charger. The cell had a rated capacity of 18kWh and it was charged from 9 percent to 80 percent — around 14.5kWh — in 12 minutes.

focused on the cell from Test Two which lost its vacuum, to prove it was not broken. VTT’s report says it cycled the broken cell 50 times (up to 90 percent of its full charge) to see what happened. VTT’s researchers said it was possible to cycle the cell, but that its capacity began to degrade after the first few, and by the end of the process, it had fallen to nearly half of its original figure. The cell itself had swelled, however, with VTT saying “the cell thickness had increased by 17 percent, and the cell pouch was firm.” Donut Lab boasted that while a lithium ion battery in this condition would likely explode, its own cell still worked.

When contacted, VTT said it did complete an assignment for Donut Lab but declined to make any specific comment on confidential client assignments.

On March 31, Verge Motorcycles posted a claiming the TS Pro Gen 2, the first to carry Donut’s solid state battery, was ready to ship. Given March 31 is the last day of Q1, it’s the latest possible day the company could announce this and say it has honored its promise. The accompanying write-up said the bike will ship with either a standard-range 20kWh battery with a range of 350km (217 miles) or a long-range 33kWh battery that should run for 600km (372 miles).

April 1

Then, on April 1, the company posted a video beginning with a fakeout scene of Lehtimäki admitting the whole thing had been a scam. One hard cut later, and the clip pivots into a Q&A, with an off-screen interviewer asking why anyone would believe Lehtimäki on April Fools Day. He dryly responded that people don’t believe him the rest of the time, but that the ambiguity provided by the occasion was a benefit. He would be able to speak more freely with less fear of censure, or so he claimed.

Lehtimäki said the series of I Donut Believe tests already published were another part of his “3D chess” strategy to get battery rivals to show their hand. And that the tests undertaken by VTT were on a first-generation battery while the company was already working on the second. He did concede that the claims around cycle life were based on estimates, and that if they wanted to prove it, they would have needed to start testing a decade or more ago. But he batted away questions about energy density, weight and size, saying you “wouldn’t ask a woman her age, and you never ask a battery its weight.” He added those questions would be answered in future, in more episodes of the I Donut Believe “complete multimedia experience.”

Consequently, the weekly video series will continue until the full details of the first generation battery have been revealed. Lehtimäki then teased that this cell would be shipping, and the videos will shift focus to the second-generation cell with far better specs. But producing the I Donut Believe series — which, it’s worth mentioning is a marketing function of the company trying to sell us a new product — was costly, and had run over budget, which has led the company to open its own merch store, including and

If you’re already facing credible accusations of perpetuating a scam, and your big reveal is to double down on misdirection, it’s not a good look. Lehtimäki ended the video by talking about how much better Donut Labs’ second-generation battery was, with a staged outtake showing a notepad listing the specs for a third-generation battery with 1,000 Wh/kg energy density, 100C charge speed and durability for a million cycles — due to be announced at a future CES.

Analysis

The release of these tests has seen interested parts of the internet engage in a level of interrogation. People have pored over every facet of the reports and videos trying to work out what exactly is inside Donut Lab’s battery. A number of prominent YouTubers have produced deep dives on the matter, each one claiming the cell is real, or not. There are countless Reddit threads where people are picking apart the voltage graphs and claims in the reports. And it seems every week there is a new revelation about what Donut’s technology is and where it came from. Plenty of people online are chasing down threads tied to energy technology companies like Holyvolt and CT-Coating, or examining the charge graphs against a . I’ll spare you the details (for now). Finnish newspaper decried the results of the fifth test, saying the cell didn’t lose its vacuum. It quoted Finnish battery expert Juho Heiska, who said the company has just used a traditional cell that is sufficiently hardy to withstand this abuse in the short term.

Even to a non-expert, there’s clearly a gap between what Donut promised and what its tests are showing. For instance, the company said it would be able to fast charge a Verge TS to full in less than 10 minutes. But, in Test Four, it took 12 minutes to get from 9 percent to 80 percent — not a bad charging time, but certainly not as swift as the company pledged. That said, if we take the company’s claims at face value, then being able to fast charge a battery at that sort of speed with just air cooling is noteworthy. At least, it will be if you can do that regularly, and one or two trips to the charger don’t leave you with what Reddit likes to call a afterward.

Unfortunately, it’s been difficult to find battery researchers willing to go on the record about Donut Labs. I sought out experts in academia who were not tied to industry backing, and so wouldn’t be accused of having a vested interest in the matter. But all of them refused to go on the record. More than one I contacted said they were well aware of the saga, and had plenty of feelings about the matter. But they were unwilling to expose themselves to the potentially intensive social media scrutiny that comes from weighing in.

I’m Donut skeptical

Personally, I’ve been suspicious of how Donut Labs has gone about demonstrating its technology. After all, if you were actually confident about your product and its technology, you would surely be able to share basic information about it. Table stakes stuff, like the weight and size of the battery cell you handed over for testing. As notes, data like that would help us all see if its energy density claims hold water. Instead, the company has engaged in an ornate kabuki which only serves to further undermine its case. You can go a long way on the back of very little trust, but the grander the promises get and the less eager you are to share evidence, the faster that trust evaporates.

And, you know how someone spends a lot of time talking around something, so as to not be caught in a deliberate lie? Donut Labs’ videos can feel a lot like that, since there are so many things it’s intentionally not making clear. Rather than taking the chance to offer even a small amount of substantive evidence to support its initial claims, it has instead moved the goalposts. So, rather than talking about the efficacy of its first-generation product, it’s dangling the second and third in front of us to hopefully distract us.

Look, I want to be even-handed, and give the company the fairest shake that I can, and obviously if the cell can deliver on its promises, I’ll be overjoyed. But we’ve all seen scams before, and until Donut Lab starts offering up a lot more data, it hasn’t earned anything close to the benefit of the doubt.