Old Rivian battery packs are getting a second act, this time helping run Rivian's own factory in Normal, Illinois.

In a notable full-circle move, the electric vehicle maker said retired vehicle batteries will be turned into a stationary energy storage system designed to cut power costs and support a more flexible grid.

According to a report from InsideEVs, Rivian said it reached an agreement with Redwood Materials to install a 10-megawatt-hour energy storage system at its Illinois factory using more than 100 retired Rivian battery packs.

Instead of sending those batteries straight to recycling, Redwood will repurpose them into a major battery project. The system is expected to cut Rivian's electricity bills when demand spikes, when electricity is typically more expensive.

The partnership builds on a growing idea in the EV world. Even after a battery is no longer ideal for powering a car, it can still have plenty of useful life left in a less demanding role.

Studies have shown EV batteries degrade more slowly than many people assume, and packs with 50% to 75% of their original capacity can still be valuable for energy storage.

"EVs represent a massive, distributed, and highly competitive energy resource," Rivian founder and CEO RJ Scaringe said in a statement. "As energy needs grow, our grid needs to be flexible, secure, and affordable. Our partnership with Redwood enables us to utilize our vehicle's batteries beyond the life of a vehicle and contribute to grid health and American competitiveness."

This kind of battery reuse could make energy systems cheaper and more resilient for companies and for the people who rely on them.

When batteries store electricity and discharge it during expensive peak hours, they can help lower operating costs. Those savings can matter for factories, large buildings, and utilities.

It also helps squeeze more value out of materials that have already been mined, processed, and built into battery packs. That means a battery can continue doing useful work for years beyond its time on the road before finally being broken down and recycled.

There is also a broader grid benefit. As electricity demand rises, including from energy-intensive AI data centers, stationary storage is becoming more important.

Systems like Rivian's can help balance supply and demand, improve flexibility, and potentially provide backup support during grid strain, outages, or extreme weather.

For everyday people, that matters because a stronger, more adaptable grid can mean fewer disruptions and lower costs over time.

Redwood has been building toward this moment since launching its Redwood Energy business last June. The company said many batteries reaching end-of-life still retain enough usable capacity to be repurposed into "low-cost, large-scale energy-storage systems" before recycling.

Rivian's project is part of a wider shift across the auto and battery industries. As some automakers slow EV production plans, extra battery capacity is increasingly being directed into stationary storage, where demand is surging.

InsideEVs also noted that Redwood made a deal with General Motors last summer to source both new and second-life battery packs for energy storage. Ford also announced in December a new stationary energy-storage unit that will attempt to make use of underutilized EV batteries for storage. 

This growing trend could open the door to more affordable battery-backed buildings, better backup power options, and smarter use of products that still have plenty left to give.

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