The Unexpected Second Lives of EV Batteries

As the switch to electric vehicles picks up pace, we speak to existing and potential customers on a daily basis who have a number of concerns regarding the switch. These concerns are mostly associated with; range anxiety, cost of switching, charging infrastructure and finally the environmental impacts of the batteries at the beginning and end of their lives.

On the concern of battery life this is present for almost all considering switching to an electric vehicle. However, EV batteries are lasting a lot longer than initially expected by many in the industry. Long-term studies carried out by Tesla have shown that after 50,000 miles the batteries maintain, on average, about 95% of their as-new capacity[1].  After 150,000 miles, the battery capacity is still at around 90%. 

Eventually, any EV battery will lose sufficient capacity that it will no longer be practical for use. A modern EV with a range of over 200 miles from a single charge will use a battery size around 60-65kWh. An EV battery is considered end of life when it has dropped to 80% of its as-new capacity. 

80% of 60kWh is 48kWh of capacity remaining. Whilst this is deemed to be impractical for continued use in an EV, this is still a significant amount of energy storage, and scrapping such batteries is never considered as an option since there is still so much residual value. 

An EV battery is designed such that it can supply power at very high rates – a modern EV motor draws power from the battery at a rate of over 100kW. By way of comparison, an average UK home can only draw electricity from the national grid at a maximum rate of 24kW.

This means that used EV batteries are given a second life in use as static energy storage systems for electricity supply, where they will be operating at a much lower level of demand than they were designed for, further extending their useful life.

In 2018, end-of-life Nissan Leaf batteries were installed as part of an energy storage system at the Johan Cruijff Football Stadium in Amsterdam to maximise the value from the 4200 solar panels they have installed on the roof of the arena[2].

A US company has also begun commercially packaging used EV batteries to sell to utility-scale renewable electricity generators to maximise value from solar and wind farm installations[3]. Due to the unpredictability of solar and wind generation, grid-scale energy storage systems like this are a great advantage. To help in balancing the national grid, they can be charged up while generation is high and demand is low, and then discharged to the grid when demand is high and generation is low.

Depending on cycle times and individual installation circumstances, EV batteries can continue to provide value for another 10 years + after being removed the car.

When the batteries have degraded to the point that they are of no more commercial value, they will be recycled in specialist e-waste recycling facilities. The Canadian company Li-Cycle is one of a number of companies currently building e-waste recycling plants across the globe that will recover “95% or more” of the lithium and other rare-earth metals from depleted batteries[4]. This will drastically reduce the world’s dependence on mining virgin ore for these metals, and manufacture and recycling of EV batteries will become a fully circular economy.