Tell us what you think. Participate in a short survey and win an Amazon Gift Card worth $ 50.

Take our short survey

Repurposing used EV batteries for energy storage

ECO STOR has designed a solution that repurposes used electric vehicle batteries to provide affordable energy storage for commercial and residential buildings.

Tjøme Kindergarten_cropped.jpg

The rapid adoption of solar and wind as clean energy sources is increasing demand for energy storage. Most energy storage solutions are, however, very expensive. There is a large unmet need for affordable options, especially for distributed energy production from rooftop solar installations on residential and commercial buildings.

Meanwhile, the popularity of electric vehicles (EV) continues to grow, as does the number of batteries needing replacing. In Norway alone, it is anticipated that over 100 000 batteries will be replaced in coming years. Today most of these batteries are sent for recycling, but they could still be used for less demanding applications.

A second life for electric vehicle batteries

When the capacity of an EV battery drops below 80 per cent, the driving distance becomes too short and the battery must be replaced. ECO STOR has developed a small-scale energy storage system that takes full advantage of these batteries’ 10 to 15 years of remaining life.

The solution uses the complete battery system, avoiding costly disassembly and reassembly, new wiring and electronics, and safety certification.

The company’s proprietary method allows users to diagnose the health of the used EV battery. Based on this, the battery management protocols are reprogrammed. A small, easily customisable controls unit is placed onto the battery to communicate with the internal electronics.

For instance, if a used battery is repurposed for a rooftop solar installation on a private home, the controls unit will communicate instructions to the battery that prolong lifetime and secure safe operations.

If the system is intended for a larger commercial building where several used batteries are connected, the controls unit will monitor and adjust the individual batteries according to the diagnostic information.

Lindhøy Energy Center_cropped.jpg

Concrete benefits

ECO STOR’s solution reduces the CO₂ life cycle emissions of EV batteries and creates a circular economy for them. It also significantly cuts the cost of small-scale energy storage.

Because repurposed batteries do not need to be repackaged, it is easy to add or remove them from the system in response to changing demands. Moreover, stringent automotive standards for handling, shipping, outdoor storage and safety are maintained.

Market potential

Battery-based energy storage is becoming more and more attractive due to increasing integration of intermittent and distributed renewable energy production. The global market is expected to grow from USD 1.98 billion in 2018 to USD 8.54 billion by 2023.

The electrification of the transport sector is an enabler for affordable energy storage, as more and more EV batteries will have to be replaced. Located in Norway, home to the largest EV fleet in the world per capita, ECO STOR is in a unique position to evaluate its solution with real customers.

The company has signed contracts to deliver second-life energy storage systems to a hotel/conference centre in Norway and to evaluate second-life energy storage in school buildings in Oslo. Its residential energy storage systems enabling private EV owners to repurpose their own EV battery will become available in 2019.

ECO STOR’s solution is validated and being prepared for pilot trials. The company will start active sales in 2019.

ECO HOUSE Battery Rack_cropped.png

Do you want to contact this company?

Register for free and connect

Create an account



Lakkegata 52, 0187 OSLO, Norway

+47 405 31 595

At a glance

  • Affordable small-scale energy storage system

  • Gives used EV batteries a second life

  • Easy to customise for residential and commercial applications



Advancing the Sustainable Development Goals