BMW second-life solution sees retired car batteries used as mobile power units

BMW has developed a new way of giving old batteries a second life by adapting them for use as mobile power units.

Made in collaboration with energy storage experts Off Grid Energy, the retired batteries will be adapted when they can be no longer be efficiently used in cars.

Both BMW and Mini electric car batteries have a warranty of up to eight years or 100,000 miles. After this period, BMW says, the battery could still retain up to 80 per cent of its original capacity. However, even the German firm admits that it is ‘inevitable’ that at some stage the battery will no longer be able to provide the optimal amount of charge required by an electric car. It’s at this point that their secondary usage will come into play.

Graeme Grieve, CEO for BMW Group UK, said: “BMW Group will have 25 electrified models on the roads by 2023 – half of them fully electric. We are delighted to work with Off Grid Energy to find a sustainable way of continuing to use these valuable batteries, even after they have put in many years of service in our electrified cars.”

The first prototype unit has already been created and uses the lithium-ion battery taken from a Mini Electric development vehicle. Thanks to a 40kwh capacity delivering a 7.2kWh charge, it could be used to provide a decent amount of power to an electric vehicle.

As more battery modules become available over time, these systems are predicted to grow in capacity up to 180kWh and provide charging rates of up to 50kW.

Danny Jones, managing director for Off Grid Energy, said: “Off Grid Energy’s business model has been built with sustainability at its core, from the way we make our products and the materials we use, through to the environmental impact of our technology. We’re extremely excited to be in partnership with BMW Group UK and use our technology to give BMW and MINI electric vehicle batteries such a valuable second use.”