BMW Group UK has announced a new partnership with Rugby-based Off Grid Energy to create a sustainable, second-life solution for BMW and Mini electric vehicle (EV) batteries.

BMW will supply Off Grid Energy, market leaders in energy storage, with battery modules to be adapted to create mobile power units, giving retired BMW and Mini EV batteries a useful second-life when they can no longer efficiently be used in cars.

Graeme Grieve, BMW Group UK CEO, 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.”

BMW and Mini EV batteries have a warranty of eight years or 100,000 miles. After this period the battery could still retain up to 80% of its initial capacity. However it is inevitable that at some stage, the battery will no longer function at an optimum level for the car – although it can continue to serve a ‘secondary use’ purpose as a mobile power source.

Danny Jones, Off Grid Energy managing director, 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 are 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.”

The first prototype unit is now up and running, powered by lithium-ion battery modules extracted from a MINI Electric development vehicle. It has a 40kWh capacity delivering a 7.2kW fast charge and will be used at BMW and MINI UK events over the next year.

As more battery modules become available over time, systems will be built with a capacity of up to 180kWh and able to provide multiple charges at rates of up to 50kW.

When these units are used to displace conventional ways of generating temporary power, the battery modules will at least double the CO₂ reduction achieved in their original use in the car, continuing their positive impact in reducing carbon emissions.

Sustainability and resource efficiency is central to the BMW Group’s strategy. Announcing initial details of the corporate strategic direction in July this year, CEO Oliver Zipse said: “How we use resources will decide the future of our society – and of the BMW Group.

“As a premium car company, it is our ambition to lead the way in sustainability. That is why we are taking responsibility here and now.”

The company, which has already sold well over half a million EVs, will have 25 electrified models on the road by 2023, with more than half of these fully electric and expects electrified cars to account for between 15-25% of the company’s global sales before 2025.

By 2021, a quarter of the vehicles sold by BMW in Europe will be electrified – that figure is expected to rise to a third by 2025 and half by 2030.