Rejoule Maximizes EV Battery Reuse and Recycling, Transforming a Six-Hour Test to Under 15 Minutes
As electric vehicle adoption accelerates, battery remanufacturing has emerged as a critical lever for controlling costs, meeting warranty obligations, and extending battery life. Yet the industry faces a fundamental bottleneck: traditional charge–discharge cycling tests that take six hours or more per battery pack. ReJoule is addressing this constraint with rapid diagnostic technology that determines battery state of health (SOH) in minutes, unlocking scalable and profitable remanufacturing and second-life decision-making.
Using advanced techniques such as Electrochemical Impedance Spectroscopy (EIS), ReJoule’s diagnostic system can screen EV battery packs in under 15 minutes. This approach dramatically reduces labor, energy consumption, and infrastructure requirements while enabling remanufacturers to process far higher volumes with greater precision.
Zora Chung, cofounder and CFO of ReJoule, explains that legacy testing methods are no longer fit for purpose. While full cycling remains accurate, it is slow, capital-intensive, and poorly suited to commercial-scale operations. “The industry is trying to solve tomorrow’s problems with yesterday’s tools,” she notes.
Why traditional cycling limits scale
Cycling has long been considered the gold standard for validating usable capacity, but its operational drawbacks are severe. Each pack must be fully charged and discharged, often taking six hours or more. If a single faulty cell is detected, technicians must disassemble the entire pack, test each module individually, replace the defective component, reassemble the pack, and then repeat the full cycling process. This creates a costly, time-consuming loop that limits throughput and ties up skilled labor.
At scale, the challenges multiply. Testing just 25 battery packs simultaneously can require a continuous 500 kW power draw, forcing facilities to invest heavily in electrical infrastructure while exposing technicians to prolonged high-voltage work environments. With EV volumes rising rapidly, the industry cannot meet future remanufacturing demand using such slow, energy-hungry processes.
Rapid diagnostics as the catalyst
ReJoule’s rapid diagnostics replace hours of cycling with minutes of targeted analysis. By measuring internal resistance and degradation signatures through EIS, the system delivers granular, actionable insights that go far beyond basic Battery Management System (BMS) fault codes. Technicians can quickly pinpoint issues such as cell imbalance or module degradation and make informed repair or reuse decisions immediately.
This capability enables true triage at the front of the remanufacturing line. Incoming packs can be rapidly classified as ready for reuse, suitable for minor repair, or destined for recycling. Instead of disassembling entire packs unnecessarily, technicians can isolate and address only the affected modules, saving days of labor and reducing the total number of tests required.
Economics that change the business case
The operational gains translate directly into compelling financial returns. In a facility processing 10,000 battery packs per year, replacing cycling with ReJoule’s rapid diagnostics can deliver a sixfold reduction in labor costs and up to a 79-fold reduction in energy consumption. Two technicians using rapid testing can remanufacture approximately 400 packs annually, compared with just 33 packs using traditional cycling methods.
The result is a 12x increase in assumed value generation and significantly faster time to revenue. What was once a high-risk, cost-heavy service operation becomes a predictable, scalable, and high-margin revenue stream.
ReJoule’s technology does more than accelerate testing—it enables a fundamentally different operating model for EV batteries. By removing the primary bottleneck to scale, it supports a more efficient, sustainable, and circular battery ecosystem designed for the realities of mass electrification.
To learn more, download ReJoule’s white paper, Scaling Battery Remanufacturing: Challenges and Opportunities.
