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The second life of car batteries

Published by on 03.05.2020 - 2 min

It is said that cats have nine lives. Batteries used in electric vehicles, for their part, have two, and the primary materials used to build them have many more. The batteries have a first life inside an automobile, then a second life as part of a stationary energy battery storage system before being recycled. Here is a short guide to the circular economy of the battery.

Life inside a car

Use in vehicles is, of course, the primary purpose of electric vehicle batteries. This first life, inside a vehicle, can last more than 15 years depending on the type of battery, how it is used, and the lifespan of the vehicle itself. These are the best years of its life!

Technology constantly improving,  batteries are able to perform better and better. These days, it is even possible to configure charging to take data from the electrical grid into account. It starts when energy demand is lower than the available supply and stops when there are peaks in demand. This smart charging avoids overloading the power grid and promotes the use of electricity that is less expensive and requires less carbon.

In the future, bidirectional charging will improve upon smart charging by offering the option to store electricity during off-peak hours or production peaks from renewable energy, then feed it back into the power grid during peaks in consumption. Linked to the electrical grid, vehicles can actually be used to store electricity to compensate for the intermittent nature of renewable energy sources producing electricity (vehicle-to-grid.) They thus play an important role in regulating the electricity grid and help in the transition to renewable energy sources. Experiments are already underway on Porto Santo Island in the Madeira archipelago and in Utrecht in the Netherlands.

The battery’s second life

In their second life, too, batteries linked to the electricity grid contribute to the development of renewable energies. Once a battery has been removed from the vehicle, its residual capacity is estimated to be 60- 75% of its initial capacity, which is largely sufficient for a second life! Batteries can be used to store energy, in particular energy from intermittent, renewable sources.

In buildings, for example, the batteries can store solar energy gathered by photovoltaic cells over the course of the day, then make it available in the evening after the sun has set. This is called a stationary energy battery storage system. For example, in France, the Syndicat Départemental d’Energie et d’Équipement de la Vendée (SyDEV) has been experimenting for several months with using secondhand Renault batteries to store energy produced by photovoltaic cells placed on the roof. This energy maximizes the building’s energy autonomy. It is used, most notably, to power charging stations for electric vehicles. Other uses are also possible for these second-hand batteries, such as propelling or providing back-up power for specialized motors. They can thus be used to power refrigeration systems, electrify runway vehicles at airports, propel boats, and more. The lifespan of each battery can thus be extended for as much as 10 years.

The last hurrah: recycling

Once it has arrived at the end of its second life, the battery still has a bit farther to go. It is time for it to be recycled in a specialized treatment center. The primary materials used to make the battery are recycled and reused to produce parts for the automobile and other industries. The goal is to minimize the need for the extraction of new materials. And so it comes full circle!

To summarize, electric vehicle batteries are part of a circular economy: they have longer lifespans and are used for multiple purposes as part of the transition to renewable energies, before eventually being recycled.


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