FFG-Success-Story: How Second-Life Battery Storages become crucial to meet future demand

Given the planned energy transition in europe, innovative storage and battery design is required to meet increasing battery demands

Batteries are of crucial importance for the optimal integration of renewable energies into the power grid. Specifically, decentralized energy storage systems – i.e., small energy storage systems – are very attractive for both grid operators and consumers: on the one hand, they are a very competitive solution for improving the coverage of the own energy demand by end users, and on the other hand, they can also help to stabilize the power grid. A rapid expansion of these energy storage systems is crucial to meet the flexibility needs of a decarbonized power system. Especially given the planned energy transition in Europe, innovative storage and control concepts as well as the simultaneous strong expansion of renewable energies are essential to guarantee a stable energy supply and to reduce CO2 and pollutant emissions.

While the demand for batteries for distributed energy storage is increasing, the electromobility sector will account for the largest share of the battery market. According to estimates for 2030, the electromobility sector will account for 85% of the total battery demand. Without a feasible circular battery value chain, the available raw materials could reach their limits. Thus, the EU committed to improve these value chains by 2030.

One challenge for the design of second-life batteries is to determine the state of the used modules. This can be done by expensive measurements for all used modules before reassembling it to a second-life battery, which increases the price.


FFG research project “BetterBatteries”

In order to avoid these measurements, to enable an optimized design and to lower the price of second-life batteries the FFG research project “BetterBatteries” has been conducted. In this project VIRTUAL VEHICLE focused on two crucial aspects of second-life batteries:

  • Understanding battery aging beyond SOH=70%: currently there is a lack of evidences on the SOH degradation during 2nd life, thus one goal of the project was to understand second-life behavior without access to first-life measurement data
  • Implementing data-driven pre-qualification of battery modules: new physics-based or data-driven tools can provide answers to understand the key parameters at the end of the first life- and determine the second-life. This can drastically reduce the need for expensive and time-consuming battery characterization testing, which in turn is critical to the economics of second-life batteries.

Optimizing Battery Aging for Second-Life-Batteries

Currently, second-life car batteries are preferably used for larger applications in the industrial sector (storage capacity in the MWh range) for grid stabilization, peak shaving, or as energy storage for the improved use of renewable energies.

One use case for the optimized use of second-life batteries that was investigated in the BetterBatteries project was “Weak Grid E-Mobility Applications for E-Charging Providers”. Due to the fact that the charging points are not occupied all the time and thus strongly depending on the user behavior, the average power needed is significantly lower than the maximum power which is required for fast charging. A second life battery storage is connected to the grid as well as to two DC fast charging points and two AC charging points.

Due to the fact that the charging points are not occupied all the time and thus strongly depending on the user behavior, the average power needed is significantly lower than the maximum power which is required for fast charging. The second-life battery storage acts as a buffer to cover the power needs during peak hours. A dedicated simulation model that includes the grid connection as well as the battery pack and the charging stations was built-up in order to optimize the sizing and operation strategy of the battery storage.

Besides weak grid e-mobility applications for e-charging providers further interesting use cases are:


  • Photovoltaics for real estate applications


  • Weak grid/Off-grid: Mobile primary power for fire brigades and similar organizations


Further studies in efficient usage of second-life batteries are recommended and planned.


Project coordination (Story)

Dr. Alois Steiner

Co-Team Leader Innovative Energy

Management & Comfort Systems


Project Partner

  • betteries AMPS GmbH, Germany
  • Grazer Energieagentur, Austria

Virtual Vehicle Research GmbH

Inffeldgasse 21/A/I

8010 Graz

The project was funded by the program “Energieforschung (e!MISSION)” of the Austrian Federal Ministry for Climate Action (BMK).
The program is managed by the Austrian Research Promotion Agency (FFG).