Second-life EV batteries excel in four-to-twenty-hour long-duration grid storage
Colin Campbell · Repurposing EV batteries for grid storage · Jul 24, 2025 · at 23:52
Colin Campbell, CTO of Redwood Materials, explains the technical advantages of deploying degraded EV battery packs in long-duration grid storage systems.
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“We can certainly play in the two hour, four hour markets with repurposed EV packs, second life packs. Where we see them really starting to shine, though, is in the longer duration. Markets. So four hour, eight hour, maybe longer, maybe 20 hour. And that's because when you are using these packs at much lower than their rated current, when you're discharging them more slowly, you can tolerate more than you could at the high C rates. So an impedance imbalance things like that become less relevant.”
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