Grading Used Nissan LEAF Electric Vehicle Batteries for Second Life Applications

Solartron EIS technology has been used by WMG at the University of Warwick to grade used electric vehicle batteries from the Nissan LEAF, for second life applications. With new algorithms and technology, the process now takes minutes instead of hours.

Image above from the University of Warwick.

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Second Life for EV Batteries

Currently, at the end of an electric vehicle’s lifetime, the battery is usually recycled by the manufacturer. However, the lithium ion battery could still have a storage capacity of >70%.

The used batteries are still suitable for less demanding “second life” applications, such as domestic and industrial energy storage. Re-using battery packs and modules is much more eco-friendly than disposing of them, or recycling them before the end of their usable lifetime.

Automotive batteries deliver some great environmental benefits, but they consume a lot of resources in doing so. Opening up a second life for batteries improves both the environmental and the economic value we draw from those resources before they need recycling. I’m delighted that by working with the partners in this project, we’ve been able to make it much easier to access those second life applications.
Professor David Greenwood, WMG, University of Warwick

Grading Used Batteries

Before re-use, the batteries need to be graded to check their capacity. Usually this is a long and expensive process.

However, a new process for grading has been developed by researchers at WMG at the University of Warwick and AMETEK Nissan. It’s much faster than traditional methods, taking minutes rather than hours.

The process has been tested with used Nissan LEAF batteries. With this greatly increased through-put, it’s now feasible to grade large numbers of lithium ion batteries from electric cars to assess them for re-use.

Grading Used EV Batteries
Image from the University of Warwick.
The number of electric vehicle batteries reaching end-of-service is set to increase from thousands to tens of thousands per annum by 2025. These batteries typically retain significant capacity and power delivery capability, and their re-use in so-called ‘second-life’ applications has been proposed as a mean to extend the battery value chain and minimise waste by deferring recycling.
Francisco Carranza, Managing Director from Nissan Energy

Nissan LEAF Batteries

Car manufacturer Nissan wanted to find ways to speed up the grading process for used Li-ion batteries from their Nissan LEAF. 50 used car batteries were used to develop the existing grading process. They were challenged to demonstrate 1MWh of energy storage by the end of 2019.

The “UK Energy Storage Laboratory” project was part-funded by BEIS (Business, Energy and Industrial Strategy) and led by NISSAN, WMG at the University of Warwick, AMETEK and Element Energy.

Testing the New Methodology

A safe, fast and robust methodology for grading used automotive Lithium-ion batteries at pack level was developed at WMG’s Energy Innovation Centre. In a pilot project, the target of 1MWh of second-life energy storage was successfully achieved.

They have developed a way of grading modules (the sub-components of battery packs) in as little as 3 minutes – a process that previously took over 3 hours.

Once graded, the packs can be relied upon to provide energy storage for products in industry and in the home, such as storing energy generated from solar panels. They can also be used to sustain a consistent energy supply, enabling more renewable but intermittent energy sources to be added to the grid.

Reconditioning car batteries has to become business as usual – it makes sense environmentally and commercially. This project has proven a scalable process to deploy reconditioning and represents a significant milestone in the UK pathway to net zero emissions.
Celine Cluzel, Director, Element Energy
Successful pilot at WMG
Successful pilot project at WMG. Image from the University of Warwick.
It’s great to hear that the University of Warwick and Nissan are collaborating in pursuit of a greener, cleaner future. Reusing the batteries from electric cars could provide a valuable contribution to the UK’s green revolution – helping us lead more efficient and smarter lives as we end our contribution to climate change by 2050. We’ve part-funded this project to help give manufacturers more options than recycling – meaning a battery that helped a driver get from A to B could then be used to help store energy used to power a home.
Lord Ian Duncan, Business and Climate Change Minister
Battery Testing
Image from the University of Warwick.
The algorithm was developed with assistance from AMETEK EIS analysers. We are currently implementing the algorithm in our new family of Solartron Analytical Battery Analyzer products, including our flagship SI-9300R model, which we expect will reduce market barriers for second life applications.
Andrew Williams, AMETEK
Ametek SI9300R Battery Cycler


The technology and algorithms developed for this project is now available in a system from AMETEK:

  • Fast SoH (State of Health) analysis in minutes.
  • More than a standard battery cycler.
  • Extra functionality for electric vehicle applications: hybrid HEV, PHEV and eV Second Life.
  • EIS (impedance) included as standard.
  • Multiple current ranges.
  • Regenerative technology for low running costs.

More Information

Blue Scientific is the official distributor for AMETEK electrochemical testing systems in the UK, Ireland and Nordic region. We’re available to answer all your questions – just get in touch:

 Contact us on +44 (0)1223 422 269 or

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