- Cell tested: Donut Lab "Solid-State Battery V1" – a pouch cell labeled DL2
- Nominal specs: 26 Ah capacity, 3.6V nominal voltage, 94 Wh energy
- Tested by: Independent third-party lab (VTT) at customer request
- Test equipment: PEC ACT0550 cell tester + Weiss climate chamber capable of -40°C to +180°C
- Actual capacity measured: 24.9 Ah (slightly below 26 Ah nominal, but within reasonable variance)
- +80°C discharge: Delivered 110.5% of room-temperature capacity (27.48 Ah vs 24.87 Ah at 24A)
- +100°C discharge: Delivered 107.1% of room-temperature capacity (27.61 Ah at 12A)
- Energy efficiency: ~89-90% round-trip efficiency observed
- Charging: All charging performed at +20°C for safety; cell accepted charge normally after both high-temp tests
Cell used a 2.4kg steel plate on top for mechanical pressure during testing
Post-100°C test: Cell pouch lost vacuum (visible inflation/deflation) but remained electrically functional
No visible damage after 80°C test; cell appeared physically intact after 100°C test despite vacuum loss
Energy density: No weight and volume was mentioned
Cycle life: VTT ran only 3 test cycles total.
Cost Claims: Nothing about cost is mentioned
Material Claims: No chemical analysis or materials analysis.
No abuse testing: No nail penetration, no overcharge, no short-circuit, no crush tests.
26 Ah nominal capacity at 1C discharge rate
94 Wh nominal energy with 3.6V nominal voltage
Operates within 2.7V – 4.15V recommended range (max charging to 4.3V)
5C charging (130A): 0-80% in ~9.5 minutes, 0-100% in ~13.5 minutes
11C charging (286A): 0-80% in ~4.9 minutes, 0-100% in ~7.3 minutes
Successfully delivered 98.4-99.6% of charged capacity even after extreme 11C charging
Tested with both one-sided and two-sided heat sinks to simulate real-world conditions
With dual heat sinks: Peak temps of 47°C (5C) and 63°C (11C) — well within safe limits
With single heat sink: Reached 61.5°C (5C) and up to 89°C (11C) — still functional but approaching thermal limit
Energy density: No weight and volume was mentioned
Cycle life: VTT ran only 7 test cycles total.
Cost Claims: Nothing about cost is mentioned
Material Claims: No chemical analysis or materials analysis.
Extreme Temperature Performance: No cold weather testing. No high-temperature testing.
No abuse testing: No nail penetration, no overcharge, no short-circuit, no crush tests.