These Batteries Can't Power a Car—but They Can Light Up a City

These Batteries Can't Power a Car—but They Can Light Up a City | WIRED

"On a barren field in Lancaster, California, where the temperature often tops 100 degrees Fahrenheit in summer, sit eight white boxes that might be a key to a greener future. Each 10 x 22-foot rectangle holds 20 battery packs that once powered Nissan Leafs. But they’ve lost some of their juice. Inside a car, they can no longer power speedy accelerations, and their 85-mile ranges have been reduced to about 55 miles.

But the batteries still work. Research suggests they may retain two-thirds or more of their original capacity. So for the past 18 months, these batteries have been living a second act: storing energy from nearby rows of solar panels. Their owner, B2U Storage Solutions, wants to know how effectively, and for how long, they can do that.
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ReJoule, a startup based in southern Los Angeles County amid strip malls and rocking oil derricks, wants to streamline that process{testing batteries for second use}. Its prototype is a lightweight, desktop computer-sized device that can diagnose in less than five minutes, and as little as 30 seconds, whether a battery is suitable for a second life. Today, the process can take hours and requires machines that can be heavier than the battery packs they’re diagnosing. ReJoule plans a second machine, the size of a dorm room fridge, to diagnose a battery pack before it’s even taken out of a car. Its tech relies on electrochemical impedance spectroscopy, which uses an alternating current scanned over many frequencies to measure the health of the materials inside a battery cell. Eventually, the company would like to see its software embedded in new batteries so they can be monitored through their stressful lives on the road. It would also like help from regulations, or at least industry standards to make the job easier."