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What is a second life battery?

Batteries aren’t dead when they come to the end of their useful first life. Second life batteries are batteries that can be applied for a different use after their initial lifecycle is over. Giving a second life to batteries, by reusing them in different but still effective ways, leads to economic and environmental benefits. The development of viable second life batteries and battery packs can reduce the amount of waste and also prevent the additional depletion of Earth’s minerals. As part of the ecosystem of solutions for the energy transition, storage and batteries are tools to enable sustainability and, at the same time, they themselves must be fully sustainable.

What are second life batteries used for?

Second life batteries are ones that have reached the end of their "automotive" life but still have a residual capacity of about 70-80%. This means they can be used in stationary systems, in combination with renewable energy generation, such as wind and solar, and/or to supply services to the electricity network. Extending the life of batteries means reducing their carbon footprint and increasing the amount of renewable energy available on the grid. It also makes electric vehicles cheaper, because it converts waste disposal costs into residual value. The EV market is one of the options available, albeit not the only one. By 2030, in Italy alone, it is estimated that 60,000 tons of electric vehicle batteries will have to be disposed of per year.
Second life batteries

Second life batteries

Batteries can have a second chance to create sustainable value, enabling a more efficient energy consumption

However, although they can no longer be used to power an electric vehicle, second life batteries can be used for other applications, such as stationary storage systems. One of Enel X’s flagship cases in this remit is the grant won by the company, together with Aeroporti di Roma (AdR), operator of Italy's largest airport Rome–Fiumicino International Airport Leonardo da Vinci, of €3.15 million from the European Innovation Fund for its airport sustainability second life battery storage (PIONEER) project.

What is the process of recycling batteries?

The reuse of batteries and recycling of the materials they contain at the end of their life are all-around sustainability goals and an effective application of the Circular Economy. The efficient use, recycling, and reuse of storage and batteries is becoming increasingly important, and is now shaping specific projects for technological development, catalyzing financing for their implementation, and creating specialized production chains for the segment.

When an EV battery reaches the end of its “first life”, there are three options for its “second”:

  • Repurposing, wherein several suitable packs are selected and combined based on residual state, capacity, et cetera, is one option.
  • Refurbishment of packs is a second viable option. Essentially packs are disassembled and then single cells are reconditioned and repacked in new modules.
  • Recycling, which involves extracting the valuable metals in the battery and re-using them.

Repurposed and refurbished packs can then be used in stationary applications which promote affordability, energy efficiency, environmental-friendliness, and sustainability.


The process of recycling a “second life battery” involves extracting the valuable materials from used EV batteries: lithium, cobalt, nickel and manganese. Given that demand for EVs is expected to see double-digit growth over the current decade, the need for lithium and cobalt is expected to increase eighty- and fifty-fold respectively by 2030.

Innovation and Sustainability


Leading the way to climate-proof technological transformation

The development of a market for viable second life batteries and battery packs can reduce the amount of waste and also prevent the additional depletion of Earth’s minerals. Additionally, repurposing EV batteries is the more cost effective solution. In order to fully unlock the potential of second-life batteries, standards that classify batteries based on performance potential and classify storage applications based on performance needs must be established. Once widely accepted standards and a regulatory regime setting broad guidelines are defined, the widespread adoption of recycled batteries offers a promising future of reduced carbon footprint and an increase in local economic activity –  all positively contributing to the circular economy.

What are the main benefits of battery recycling and reuse?

Electricity storage systems and batteries play a strategic role in the energy transition value chain, because they are essential to creating a shift to more effective, efficient, and competitive electrification solutions in several areas, thereby reducing the need for the fossil fuels that contribute to global warming.

Second life batteries have clear environmental benefits in both the extraction and disposal stages.


These include:

  • A reduction in mineral extraction and an increase in resource conservation, thereby preventing the further depletion of the Earth’s minerals and avoiding energy- and emission-intensive material processing
  • A reduction of waste being dumped in the environment
  • The reuse of materials after they have been recycled.


The process driving the energy transition for a sustainable world

Giving a second life to batteries by reusing them in different ways also has economic benefits. It makes electric vehicles cheaper because it converts waste disposal costs into residual value, further fostering the energy transition and triggering a virtuous cycle of decarbonization. The efficient use, recycling and reuse of storage and batteries is also shaping development projects and their funding and creating specialized production chains for the segment.

What is an example of a second life battery project?

A second life battery project is meeting the energy needs of Melilla, Spain, a seaside town of 86,000 people. Enel X constructed an energy storage solution at its thermal power plant from 78 second life battery packs provided by auto manufacturer Nissan, which will reduce the risk of power cuts in the autonomous city. The system can deliver power of up to 4 MW and a maximum stored energy of 1.7 MWh. The project is a concrete example of the benefits of the circular economy, extending the life of spent battery packs by six years, and is a cheaper alternative to stationary power storage batteries. Second life batteries are also well suited for large facilities. PIONEER  is a 10MWh second life battery project using batteries from three different car manufacturers storing excess power produced by a 30MW solar photovoltaic plant powering Rome–Fiumicino International Airport Leonardo da Vinci,  which aims to become CO2 neutral by 2030. Enel X and Aeroporti di Roma (AdR), the Rome airport’s operator, won a grant of €3.15 million from the European Innovation Fund in a consortium that also includes Germany's Fraunhofer Institute for Solar Energy Systems, which carries out research and development for the energy transition. PIONEER is one of 32 projects selected by the EU to bring innovative low carbon technologies to the market. Another good example is being showcased by WMG (the Warwick Manufacturing Group) at the University of Warwick in the UK. The team of researchers began testing EV batteries in 2019 for repurposing to then be used as small battery energy storage systems (BESS) for off-grid locations. As a result, the University of Warwick has now launched a full-scale EV recycling facility.

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