The battery world has been captivated by Donut Labs, a company promising revolutionary energy density and 100,000 cycle lifespans. But after their latest “Test Six” which turned out to be an April Fool’s Day interview rather than a data drop the internet’s detectives have uncovered a web of inconsistencies that raise serious questions about what’s real.
Here are the biggest red flags uncovered so far.
The 100,000 Cycle Admission
In the recent interview, the CEO confirmed what many suspected: the 100,000-cycle claim was never measured. “Of course not,” he said, noting they would have needed to start testing a decade ago. It was merely a projection from a much smaller sample.
The Altered Report
Perhaps the most damning evidence is a redacted VTT test report. When comparing the published PDF to the version shown in Donut Lab’s own video, key differences appear. The original mentioned a low-temperature discharge test, but the final public report removed that reference entirely. Critics ask: Did the cold test fail, or was the data unflattering?
The Missing Weight
The company continues to dodge a simple request: put the cell on a scale. The CEO joked, “You never ask a battery its weight.” However, leaked SGS reports from a linked supply chain suggest a cell weighing roughly 312 grams. At that weight, the energy density calculates to around 268–291 Wh/kg far short of the 400 Wh/kg Donut has marketed.
The “Factory” vs. The Reality
While investor letters promised gigawatt-hour production lines, investigators traced the actual facility to a converted duty-free retail building in Finland. For context, battery giants like QuantumScape have spent billions on clean rooms; Donut’s operation appears to be starting in a repurposed shop.
The Verdict
While the marketing machine is strong complete with tinfoil hat merchandise and Finnish humor about “continued ambiguity” the science is struggling to keep up. As one analyst noted, building batteries is incredibly hard; startups with billions have failed. For now, the community waits for a real test, hoping the missing cold-weather data eventually thaws.
