ReJoule: Solving the Issue of EV Battery Quality

By: Sharjeel Sohaib


Dec 18, 2021


ReJoule was founded in 2017 and is based in Signal Hill, CA. The startup received $1.2M from a Phase I SBIR and Phase II grant from the National Science Foundation, $600K from CalSEED guided by California Energy Commission May 2020, and we were awarded a $3M grant to validate second-life batteries, also by the California Energy Commission.

The ReJoule Technology

Rejoule established characterization techniques to quickly and accurately grade batteries. These techniques are called electrochemical impedance spectroscopy (EIS) and hybrid pulse power characterization (HPPC). These are diagnostic tests that unlock battery parameters that track degradation (e.g. loss in active lithium, SEI layer growth, etc).

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ReJoule: Solving the Issue of EV Battery Quality 5

Founders and Use Cases

The startup was founded by Steven Chung and Zora Chung. The key use cases of its EV battery business are:

  • Battery Evaluation
  • Battery Testing
  • Battery Second Life Mgmt.
  • Real time EV Battery insights

Inland Empire and EV Batteries

The Inland Empire was ranked 10th best in EV adoption, we reported earlier in September this year. San Jose, San Francisco, and Seattle, and Los Angeles led the adoption for the electric vehicles.

The report was based on data assessed for various factors such as:

  • Residential charging stations
  • EV infrastructure including public
  • Number of registered electric vehicles
  • HOT (high-occupancy toll) lanes for EVs
  • The cost of an e-Gallon (cost of charging a vehicle using electric when compared to a gasoline-powered one)

Based on a report by the International Energy Agency (IEA), one of the two factors that impact the most in enabling EV adoption is the battery industry. And, with the world gradually moving towards phasing out the internal combustion engine, here’s a snapshot of how countries plan to do away with the tradtional engines.

Iea Ev
Source: International Energy Agency

It’s only a matter of a few years that ReJoule’s product and service area will be in high demand. It is not just startups like Rejoule and Instant ON trying to solve the problem of solar energy storage and battery charging; there’s a similar push at the utility-scale electrification of the energy supply chain. Last month, Startempire Wire reported about San Bernardino County’s plan to have a 650 Megawatts (MW) Daggett Solar Power facility that will produce up to 650 megawatts (MW) of power and include up to 450 MW of battery storage capacity of approximately 3,500 acres of land.


  • Avatar Of Sharjeel

    Sharjeel joined Startempire Wire as emerging technologies editor. Earlier, he worked at Silicon Canals, a leading English language technology media source for the Benelux and wider Europe. He covered the European technology and startup ecosystem digging into latest funding rounds of startups.


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