Celebrating ReJoule, VentureWell’s 2024 Sustainable Practice Impact Awardee

ReJoule, OPEN 2024 Sustainable Practice Impact Award; photo of ReJoule’s Zora Chung

ReJoule was honored with VentureWell’s 2024 Sustainable Practice Impact Award for creating a circular economy for lithium-ion electric vehicle (EV) batteries. As EV sales skyrocket, the need to measure EV battery life and find uses for partially depleted batteries has become more urgent: These are the problems ReJoule has stepped in to solve. We sat down with Zora Chung, co-founder and CFO of ReJoule, to talk about the evolution of the company and her path to entrepreneurship.

Before ReJoule won VentureWell’s 2024 Sustainable Practice Impact Award, before Zora Chung even imagined founding ReJoule or revolutionizing electric vehicle (EV) battery (re)use, she was a finance manager at Walmart—and she was extremely good at it. There is no one path to entrepreneurship; this is Zora’s story.

An Entrepreneur Gets Her Start in Corporate

At Walmart, Zora worked on the corporate side, helping to bring the startups the company acquired into the company structure, and she loved it. “I learned that I actually really enjoyed problem-solving, and I enjoyed building,” Zora says. She was in charge of evaluating new and existing business models, optimizing those companies for scalable growth. She learned something else about herself, too: “Once I got something set up and running, I was ready to move on to the next thing. I realized I did not want to be the person maintaining it.” Though she wasn’t ready to leave the corporate world just yet, Zora recognized that this was a character trait that would serve her well in building a fast-growing, fast-changing startup. She was curious about the possibility of starting her own company someday. Her parents run their own business, and they always encouraged her to consider the possibility.

Zora Chung’s leap into entrepreneurship came when her brother, Steven Chung, gave her a call. “He was experiencing a problem with modeling the health of EV batteries, to the point where he actually thought he was doing something wrong,” she explains. They started talking to other people in the industry and realized the issue was widespread. Without a technology that can accurately determine the health of a battery, the battery’s secondary usefulness is severely limited.

A record 1.2 million EVs were sold in the U.S. in 2023; the worldwide number for 2022 is 6.5 million, and both figures are expected to go up. The lithium-ion batteries in these vehicles will eventually be retired. What happens then?

Founding a Circular Economy for Lithium-Ion EV Batteries

Zora and Steven Chung imagined repurposing these batteries, turning them into valuable power sources instead of hazardous waste. For Zora, this was exactly what she needed to take a leap and transform her career. Steven and Zora founded ReJoule to create a circular economy for EV batteries—he as CEO, she as CFO.

Leveraging her business acumen and love of building processes, Zora came onto the team leading “all things non-technical,” which included the support functions—finance, human resources, and legal—as well as outward-facing functions like marketing and business development. “I wasn’t sure if this skill set I had would translate. I’m not an engineer,” she says. “But you need all types of people to run a business. The passion for solving the problem is what unites everyone.”

Fall in Love with the Problem, Not the Solution

Zora Chung accepting the 2024 Sustainable Practice Impact Award on behalf of ReJoule at OPEN
Zora Chung accepting the 2024 Sustainable Practice Impact Award on behalf of ReJoule at OPEN

At first, Rejoule’s approach to the problem was to repurpose lithium-ion batteries from vehicles like golf carts. “There’s a huge benefit of using lithium-ion versus acid from the maintenance and longevity point of view,” Zora says. However, when they visited a few golf courses, Zora and Steven quickly learned that most carts were leased. It didn’t make sense to convince a small number of owners to make the transition. “From there, as we talked to people, we learned where there could be a bigger problem, within the automotive space, given the large amount of EVs that were going to market.”

One of Zora’s favorite sayings about entrepreneurship is “fall in love with the problem, not the solution.” She and her brother were obsessed with understanding EV battery life, and they knew this could be a game-changer for the industry. But golf carts weren’t the solution their company needed. Like so many other entrepreneurs, they had to pivot.

Using Pattern Recognition To Stand Out in a Crowd

Zora dove into research mode. Her goal was to understand the parts of the EV industry where the health remaining in a battery was crucial data that people would pay for. One of her prime tools for information-gathering was attending conferences, where she could get in front of lots of people who were there to network.

The automotive industry—like the EV industry—has historically been male-dominated, and it has been Zora’s experience that this remains true today. As a newcomer to the scene, Zora knew she needed to approach the situation with a problem-solving mindset. “It can be unnerving, but I would sometimes use the fact that I stand out to my advantage.” She identified the fact that many people would dress the same at conferences she frequented, almost like a uniform. “I would wear a bright blue dress or a bright red shirt; that way, if there was someone I really wanted to talk to and they were busy at that time, it would be easy for them to find me.” Since she had broken the pattern already, Zora chose to break it further, intentionally.

Zora and Steven used what they learned to hone the solutions that Rejoule offers. ReJoule’s technology, a management system that accurately measures EV battery life, provides a diagnostics and grading report to maximize battery usage—and it’s already revolutionizing the clean energy space. “I really enjoy hearing from our customers in terms of the problems that they have and how we’ve been able to help them,” Zora says.

Mentorship and Millions in Funding Help a Sustainability Startup Grow

Zora Chung (third from left) posing with Stephen Chung (third from right) at the American-Made Solar Prize Round 6
Zora Chung (third from left) posing with Steven Chung (third from right) at the American-Made Solar Prize Round 6

In Spring 2023, ReJoule participated in Aspire Climatetech, VentureWell’s customized training program designed to support seed-stage startups at the investor engagement stage. Investors mentor the startups to prepare them for the fundraising process. “Working with the different mentors was really helpful,” Zora says. “Their different vantage points challenged us, because we can get siloed into thinking about how we approach our business. It’s really tactical, important support.” Steven and Zora still keep in touch with the mentors they worked with as part of Aspire. Some have expressed an interest in investing in the company.

For now, ReJoule is funded with an array of awards and grants that show widespread support for their innovative and sustainable business. ReJoule made history as the first team to win both the $500,000 grand prize and the $50,000 Justice, Equity, Diversity and Inclusion (JEDI) contest across all rounds of the American-Made Solar Prize (pictured at right). They have been awarded a total of $19 million in grants, including the U.S. National Science Foundation (NSF) Small Business Innovation Research (SBIR) Program Phase I and II. “If you have a hardware product and you don’t have something already in the market, investors classify it as technical risk,” Zora says. “Organizations like NSF purposely fund technical risk through grants. That’s when you’re more likely to get investment early on to prove out your technology.”

Reusing and Repurposing EV Batteries for Big Sustainability Impact

ReJoule battery energy storage system at the American Museum of Ceramic Arts in Pomona, California
ReJoule battery energy storage system at the American Museum of Ceramic Arts in Pomona, California

ReJoule is installing their first battery energy storage system at the American Museum of Ceramic Arts in Pomona, California, using repurposed electric delivery truck batteries (pictured at left). This is an exciting proof of concept for the company.

They also published a white paper on how to handle batteries that are being decommissioned, which is available for download on their website. Steven and Zora are looking into the used EV market as well, where their technology would add crucial information about the life left in the battery, which can vary widely depending on use and storage as well as age. There are many valuable potential uses for their clean technology in our power-hungry world.

Looking ahead, Zora Chung is motivated by the impact they’re already making in the mobilization of climate change solutions. “We’re enabling something that is sustainable to be even more sustainable—reducing the greenhouse gas emissions associated with the manufacturing of batteries by enabling reuse and repurposing,” she told us. “Technology like ours doesn’t really exist on the market today, and what we’re doing has never been seen by the world before. It’s very cool to be innovators.”

We are thrilled to award ReJoule with our 2024 Sustainable Practice Impact Award, and we anticipate even greater success from the company in the future.


The American-Made Solar Prize Round 8 is now seeking innovators, entrepreneurs, and those with an idea to revolutionize the solar industry. Apply by September 26.

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