Second life for repurposed EV batteries in off grid locations

EV batteries are being repurposed by researchers at WMG, University of Warwick for use as small energy storage systems (ESS) for off grid locations.

second life
Prof James Marco in the lab (Credit: WMG, University of Warwick)

With 2kWh of energy capacity, the repurposed units are expected to find use in developing countries or isolated communities where they could provide electricity to small shops, farm holdings, or residential homes.

“When an electric vehicle’s battery reaches the end of its useful life it is by no means massively depleted,” said Prof James Marco, lead researcher on the project. “It has simply reached the end of its useful life in a vehicle. It is generally accepted that an EV battery has reached end of life when its capacity drops to 80 per cent of a fresh battery. While this is no longer enough to satisfy drivers, it remains immensely useful for anyone who seeks to use the battery in a static situation.”

Partially depleted batteries have the potential for a second life as long as they can be used reliably, sustainably, and cheaply in remote locations. According to WMG, challenges ahead of this goal include protecting the lithium-ion cells from over-charge and discharge, ensuring ESS compatibility with other used battery cells and modules from other manufacturers, and developing an easy and economical maintenance regime.

The team said it overcame these challenges with the help of the WMG HVM Catapult and Jaguar Land Rover who supplied batteries and components from the Jaguar I-PACE. The team designed a new Battery Management System (BMS) and packaging that allowed them to create a working and portable prototype ESS which included: standard low-cost components for control, communication and safety functions, multiple 12V DC sockets and 5V USB charge ports, and a simplified control system for easy integration and deployment.

The prototype can also be charged via reclaimed laptop chargers and can be interchanged with other modules without having to recalibrate the BMS.

“This is a great result that not only provides a highly efficient repurposing solution for automotive batteries but which could also change lives in remote communities,” Prof Marco said in a statement.  “We are now looking for support to allow these new units to be further developed and tested in remote or off-grid locations.”

The research project was part of the Innovate UK funded Project: 2nd hEVen (2nd-Life Energy Storage Systems) and is supported by the WMG High Value Manufacturing (HVM) Catapult.