The Battery From The World’s First Production Solid-State EV Was Independently Tested And It Raises More Questions Than Answers

Back in January, Donut Lab and Verge Motorcycles stunned the electric vehicle world by announcing what they called the “World’s first production vehicle with an all-solid-state battery.” The Donut Lab battery that powers this motorcycle is considered the “holy grail” of batteries. The battery gives the motorcycle 370 miles of range, can be charged in only five minutes, delivers 400 Wh/kg, is cheaper to make than lithium-ion batteries, and is made out of 100 percent green materials. All of these claims were made without any testing, causing experts to raise a red flag. Now, Donut Lab’s battery has had an independent test, and somehow, it raises more questions than it answers.

I was a mix of both excited and skeptical when I wrote about the new solid-state version of the Verge TS Pro in January. I’ve been a huge fan of Verge’s weird hubless rear wheel. I’ve also championed the company because, unlike so many startups, it advanced past shiny renders and breathless press releases to actually put motorcycles into production.

The lithium batteries inside production electric vehicles today have some known limitations. They charge only so fast, and their energy is only so dense. If you’re an EV owner, you’re probably used to waiting at a fast charger for around 30 minutes or so before continuing on a journey. Today’s battery density also means that, in order to get a good range out of an EV that’s doing towing or hauling, tons of batteries have to be piled into the vehicle, weighing it down and making it more expensive. Thermal runaway events in today’s batteries can sometimes be a problem, as can degradation over a very long time.

The limitations of today’s battery technology are most apparent on electric motorcycles sold in America and Europe. Manufacturers have to be careful with how they deploy batteries in electric motorcycles. Too many batteries and the bike will have good range, but it’ll also cost a small fortune and attract few buyers. Too few batteries and the bike will be cheaper, but might not have an attractive range for some riders for the price.

Solid-state batteries have been seen as the ultimate kind of power source. The promise of the solid-state battery is charging that can happen as nearly fast as you’d fill a gas tank, better energy density, lighter packs, more stable chemistry, and degradation so minimal that the battery should last the life of the vehicle.

Solid-state experiments have been going on for a long time, with huge names like Toyota, CATL, Volkswagen, BYD, Nissan, and Honda all hard at work developing a workable battery. For example, Toyota has been working on the tech for nearly two decades and is still at least a year or two out from producing its first production battery. Volkswagen and its brands have been cooking up solid-state technology since 2012. In September 2025, Volkswagen, QuantumScape, PowerCo, and Ducati unveiled a functional prototype electric motorcycle that had a real and working solid-state battery.

So, these batteries do exist, and they are out there. But nobody has made that impressive first step to put a solid-state battery into a production vehicle. That was until last month when Verge Motorcycles and Donut Lab made their announcement. The Verge TS Pro with a solid-state battery is on sale right now. Deliveries for existing orders are supposed to begin this quarter, with future orders expected to deliver in the fourth quarter. This motorcycle is something you can throw money at right now.

There Have Been Skeptics

Both companies sort of shocked the EV sphere with their announcement. Verge Motorcycles has been around since 2018, while Donut Lab was founded in 2024 and announced in 2025. Understandably, folks wondered how these little Finnish startups managed to leapfrog industry titans to launch the world’s first solid-state battery production vehicle.

The skeptics had good reason to question Donut Lab’s press copy. The company more or less claimed it had achieved the holy grail, but offered no proof. Donut Lab and Verge Motorcycles had no patent disclosures, no demonstrations of the tech, and not even any research papers. It didn’t even have any internal testing to offer anyone. The press releases just claimed the achievement, and that’s it.

According to Electrek, one of the biggest voices questioning Donut Lab was Yang Hongxin, chairman of China’s Svolt Energy. Hongxin minced no words, via Car News China:

“That battery doesn’t even exist in the world; all the parameters are contradictory… Any person with even a basic understanding of the technology would think it’s a scam.” Yang said. Yang also pointed out that it is “too early for the industrialization of all-solid-state batteries,” and criticized the excessive hype in the industry and capital markets.

Woof. Svolt is another player in this battery space. The company originally started as the battery development group within Great Wall Motor. In 2018, it was spun off into Svolt Energy Technology Co., Ltd. and has been working on its own solid-state battery project. Svolt says it finished development of its first-generation solid-state battery in November 2025, and it’s due to go into production sometime this year. The battery is expected to have an energy density of 270 Wh/kg.

According to Electrek, Donut Lab CEO Marko Lehtimäki didn’t take what Hongxin said too kindly, and noted that he’s putting not just his own reputation on the line, but the reputations of Verge Motorcycles and Donut Lab. Indeed, if this battery were all smoke and mirrors, I cannot imagine the fallout would be particularly good for anyone involved.

Donut Lab Gets Its Battery Independently Tested

In response to the critics, Donut Lab launched a website and video series called “I Donut Believe.” Donut Lab’s website doesn’t even hide that people have accused the company of being scammers.

Each week, Donut Lab seeks to prove each of its claims with a video. To make sure the skeptics are satisfied, Donut didn’t test the battery itself. Instead, the battery went to the state-run VTT Technical Research Centre of Finland for third-party verification. Now, before we continue, here’s what I wrote about this battery in January:

Lehtimäki claims his team has made a battery that can charge in only five minutes, will last more than 100,000 cycles with almost no degradation, is cheaper to make than lithium-ion batteries, delivers 400 Wh/kg, and is made out of 100 percent green materials. Simply put, Verge and Donut Lab claimed to have built the holy grail of batteries.

[…]

Donut Lab claims that this battery is better than any other in that it retains 99 percent capacity in minus 30 Celsius and also when it’s above 100 Celsius, unlike lithium chemistry. Donut Lab also says you can run the battery to zero or charge it to 100 percent as many times as you want without hurting it. As for lifespan, Donut Lab says it’ll last the entire life of the vehicle, making the threat of having to replace a worn battery a thing of the past. The company then talks about these cells not having thermal runaway problems, weighing less than lithium batteries, and, somehow, even costing less to make than lithium batteries.

As if all that wasn’t unbelievable enough, Donut Lab then claims, “In fact, we found ourselves designing a slower charging speed so riders can plug in and actually have time to drink a latte and enjoy it instead of downing an espresso and rushing back to their bike.” Weirdly, Verge also says that its version of the Donut Battery will last for 10,000 cycles rather than 100,000.

Here is Donut’s first “I Donut Believe” video:

The first VTT report (VTT-CR-00092-26) has been released, and it covers charging performance. You can read it by clicking here. Otherwise, here is the test summary:

The aim of the project was to conduct independent charging performance tests on the energy storage devices supplied by the customer, which the customer identified as solid-state battery cells. Based on the results of the initial capacity test within the recommended voltage range, the nominal capacity was determined to be 26 Ah.

The cell was charged at a 5C rate, that is 130 A, until the maximum charging voltage of 4.3 V was reached, followed by a constant-voltage charge at 4.3 V until a charge capacity of 26 Ah was achieved. The cell was charged also at an 11C rate, that is 286 A, under the same procedure: constant‑current charging until 4.3 V, followed by constant‑voltage charging until reaching 26 Ah.

The test was carried out using one-sided and two-sided heat sinks to simulate different levels of thermal management comparable to real-life applications. Before and after each charge, the cell was discharged at a rate of 1C until the voltage reached 2.7 V to measure the capacity and ensure a consistent initial condition.

The battery was subjected to seven tests, which put the pack through seven cycles. Five of those cycles were fast-charging, and three of the fast-charging cycles were done at 11C current. The tests also involved either the use of one or two heat sinks. Here’s VTT’s summary of the 11C tests:

During the test #3 (the first 11C charge test), the cell was placed between two heat sinks. The initial surface temperature of the cell was 26.5 °C, and the highest recorded temperature during the test was 63 °C. This test followed the 5C fast-charge test, which ended with a standard discharge.

During the test #6 (the second 11C charge test), the cell was placed on top of a single heat sink. The first attempt was interrupted when the surface temperature reached the safety limit of 90 °C. After a four-minute cooling period, the test was resumed. Following this run, the cell was strapped to the heat sink to improve thermal contact, and consequently, heat transfer. The test was repeated once the cell had both discharged and cooled sufficiently.

During the test #7 (the third 11C charge test), the cell was placed on top of a single heat sink. The initial surface temperature of the cell was 27 °C and the highest recorded temperature during the test was 89 °C. This test was conducted after the previous run, which ended with a standard
discharge.

This 11C current charging test was genuinely impressive as the pack charged from completely dead to 100 percent in just 7.5 minutes at the longest. The time to charge from dead to 80 percent is equally great at only 4.5 minutes. That’s awesome, and confirms that Donut Lab made a battery that charges seriously fast.

The other interesting portion of the 11C test is just how hot the battery got. Donut Lab says its battery does not need active cooling, unlike lithium batteries. However, as the VTT test shows, the battery does get hot during charging, but it looks like there is a sufficient amount of passive cooling that can be used to keep the battery in safe margins. Here’s what Donut Lab told The Verge after the test:

“Unlike other solid state batteries requiring high compressive pressures and undergoing volume changes of up to 15-20% during recharging cycles, the Donut Battery does not require special compression or more extensive cooling,“ Donut Lab CTO Ville Piippo said in a statement. “This greatly simplifies the structure of battery packs and enables solutions that are cost-efficient, powerful, and better than traditional lithium-ion batteries in terms of energy and power density.”

So, to Donut Lab’s credit, I think it sufficiently proved that its solid-state battery can charge fast. But the test answers no other question. Somehow, there are still more questions than answers.

More Questions

The 400 Wh/kg energy density hasn’t been confirmed, and neither has the claim of 100,000 cycles with minimal degradation. We’re also no closer to finding the chemistry of the battery, its extreme temperature performance, or how much the battery costs to make. Further, we don’t even know how many times the battery can be charged at 11C levels. The Verge notes that the reveals thus far also don’t tell us how Donut deals with the so-called “dendrite issue,” a condition where microscopic stalagmites grow from anode to cathode, causing a short over time.

There’s also a rumor out there that this isn’t a true solid-state battery, but a supercapacitor. Donut Lab has denied that it is rebranding a supercapacitor from Nordic Nano, but it also won’t tell anyone about the chemistry of the battery.

Then there’s this “I Donut Believe” video series. Publishing a video a week is sort of weird. It’s unclear why Donut is doing a video a week, but I think it would have been a better move to publish the results all at once rather than drip-feeding them a week at a time like a season of Fallout. But I guess doing a video a week means that Donut and Verge will stay in the news for multiple weeks.

Well, Donut Lab has my attention. This whole thing is honestly wild because, really, there are only two outcomes from this. Either Donut Lab is vindicated and is proven to have leapfrogged the rest of the world, or the whole thing falls apart, and maybe we’ll get a new documentary to watch on Netflix one day. If Donut Lab pulls this off, it could be a game-changer for all EVs. Imagine if you could charge an EV as fast as you could fill a gas tank, that EV could go several hundred miles on a charge, and those batteries cost less than lithium.

So, you bet I’ll be watching “I Donut Believe” every week because I’m honestly on the edge of my seat. This could be the breakthrough the industry has been waiting for. Or it could be a disaster. I sincerely hope it’s the former.

Top graphic mages: Verge Motorcycles; Donut Lab