I Donut Believe - Presenting Third Party Results

3 min read Original article ↗

A dark, dramatic spotlight highlights a central chat message box, surrounded by blurred, floating chat bubbles with various skeptical and sarcastic comments. The background is black and the mood is mysterious and critical. A dark, futuristic object is partially visible against a black background, with negative comments about credibility and skepticism floating above it in grey speech bubbles. A dark, blurred image of a tech device with overlaying blurred chat messages, including phrases like "Why are you guys lying?", "Where is the battery?", "Vapor ware king," and "Why does this sound too good to be true.

White text on a light background reads "DONUT" with a red circular outline and a lightning bolt inside the "O." The word "BELIEVE" is faintly visible below.

Fair enough. Here you go.

Third Party Testing

This website serves as the platform for publishing validation results and technical documentation related to the Donut Solid State Battery. Donut Lab has commissioned the internationally renowned VTT Technical Research Centre of Finland to conduct independent measurements of the battery’s performance and key characteristics. Unless otherwise stated, all tests presented here have been conducted by VTT. Full reports will be published alongside detailed video documentation that walks through the procedures, showcases the test setups, and explains the results.

A man with a beard and a baseball cap, wearing a dark blazer and black shirt, gestures with both hands while speaking in a modern office with large windows and city views.

Introducing “I Donut Believe”

Donut Lab has commissioned internationally respected VTT Technical Research Centre of Finland to independently measure the performance and characteristics of its solid-state battery. Through third-party testing under controlled research conditions, Donut Lab provides verified data to support its performance claims. In the video, CEO Marko Lehtimäki explains the company’s perspective and the rationale for launching the series and publishing the results in this format.

Watch the launch video

A close-up of a rectangular lithium-ion battery cell with yellow tape on its edges, labeled "D13," connected to wires and metal terminals, resting on a metal rack.

Fast Charge Performance Test

The first independent test of the Donut Solid State Battery, conducted by VTT Technical Research Centre of Finland, evaluates its charge performance under demanding conditions without active cooling. The cell was tested at both 5C and extreme 11C charge rates, confirming previously stated fast-charging targets, including a 0–80% charge in just 4.5 minutes at 11C. The results demonstrate exceptional charging capability alongside stable thermal behavior, providing verification of the battery’s high-power performance.

Watch the video Download full VTT test report

A close-up of a hand pressing a metal plate onto a rectangular battery cell, with a yellow piece of tape and a thin wire attached to the cell, likely for testing or assembly purposes.

High Temp Performance Test

The 2nd independent test of the Donut Solid State Battery, conducted by VTT, evaluates its capacity and operational stability under sustained high-temperature conditions. At 80°C, the battery delivered 110% of its nominal room-temperature capacity with improved efficiency due to reduced internal resistance. After multiple hours at 100°C, it maintained approximately 107% capacity and recharged to full without degradation, confirming stable performance in environments exceeding the safe operating limits of conventional Li-ion batteries.

Watch the video Download full VTT test report

Close-up of an electronic component labeled "DL1" with wires attached using clips and yellow tape, placed on a white surface. The setup appears to be part of an experiment or testing procedure.

Self-Discharge Test

The 3rd independent test of the Donut Battery, conducted by VTT, evaluates its charge retention over an extended idle period. The cell was connected to a battery tester for ten days, with voltage measured every 10 seconds. Cell voltage stabilised within the first 10 hours and remained level for the remaining nine and a half days, confirming normal battery-type charge retention – not the rapid linear discharge characteristic of supercapacitors. The results demonstrate stable, predictable energy storage suitable for real-world vehicle applications.

Watch the video Download full VTT test report

A bright green electric motorcycle is parked at a charging station while a person stands nearby. The display on the charger shows charging information. The scene takes place outdoors on a paved area.

Verge Motorcycles

Sneak Peek: Fast Charging Solid-State Battery Pack

Unlike the previous instalments, this test was not conducted by VTT. It was captured at a public charging station during a system validation session with our customer Verge Motorcycles. A previous-generation mule bike equipped with a Donut solid-state battery pack demonstrated pack-level 5C fast charging on the standard range variant — an 18 kWh (nominal capacity), fully air-cooled design. Three times faster charging than the previous model year, and the fastest of any production electric motorcycle.

Watch the video

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