Nissan has a plan for used Leaf batteries: powering buildings

• Many wonder what will happen when an electric car battery is no longer useful for the vehicle.
• Of course, EV batteries can be recycled — but they can also be repurposed for energy storage.

One of the biggest challenges to the auto industry's multi-billion-dollar push to electrify lies in the batteries. What happens when millions of used electric car batteries aren't useful in a vehicle anymore?

Nissan's latest move with a budding startup in the battery-repurposing space could be a solution to that looming problem. It might also answer concerns people have about the impact of EVs on the grid.

Nissan will work with Bay Area-based startup Relyion Energy to retire batteries from its well-known Leaf EV, Relyion announced Monday.

After all, used batteries are chock-full of valuable materials like lithium, nickel, and cobalt. And one estimate suggests that used batteries still have about 80% of their life left even after juicing an EV for several years.

But a lot of expense and resources were used to make functioning EV batteries. If it doesn't make sense to tear a battery apart in order to recycle its materials once it can't power an EV anymore, it could still be used in other ways.

Through Nissan's 4R business (a division established in the early days of the Leaf that includes recycling, reuse, reselling, and refabricating), Relyion will be charged with taking spent battery packs recovered from Leafs, testing their level of health and state of charge, and putting them in second-life energy storage.

How used EV battery reuse works

More simply put, this startup will take your Leaf battery and, if it's still good, use it to power something else, like a house or something utility-scale.

"A majority of these batteries actually have a very good state of health that is left over once the car is retired, but they're just not suitable for cars anymore," Surinder Singh, Relyion CEO and co-founder, told Insider. "They can be of very good use on the stationary and energy storage side.

"Why would somebody prematurely kill them rather than utilizing them for a very long period of time?" he added. "These batteries can last for 15 to 20 years in addition to, let's say, the 10 years that they were in operation in the car. It makes a lot more sense to actually utilize them for as long as possible, and then at the end of the day, when they reach their true end of life, then recycle them."

How it works: Nissan will recover used Leaf batteries and supply them to Relyion. Relyion plans to start putting these batteries in large energy storage systems for businesses in various industries this year. It is targeting full-commercialization with more customers and residential applications in the second half of 2023.

It could cut the commercial and industrial sectors' energy bills, in particular, and reduce peak demand charges.

That residential point might be especially pertinent. Nissan has upped the capacity of its battery packs over several generations. But even its earliest gen EV batteries could be used to power a home.

"One car battery pack would be suitable for a couple of homes," Singh said — and not just in the event of an emergency. 'It can be used for backup power. It could be used for like public safety power shut offs that are unfortunately quite common in California. They can be used for daily use."