Second-life battery

Second-life battery

A second-life battery is a used battery — typically from an electric vehicle — that is reused for stationary applications such as Battery Energy Storage Systems (BESS) after its original automotive use has ended. It provides a sustainable and cost-effective alternative to new battery systems.

How it works

Batteries in electric vehicles gradually lose capacity over time. When their performance drops to around 70–80% of the original capacity, they are usually no longer considered suitable for mobile use.

However, they can still be effectively used in stationary energy storage, where factors such as weight, size, or maximum driving range are less critical.

After technical testing, refurbishment, and sometimes reconfiguration, the battery modules are integrated into stationary BESS solutions.

Typical applications

• Commercial and industrial storage systems with a focus on sustainability
• Self-consumption optimization in combination with PV systems
• Storage solutions for grid services or peak shaving
• Modular storage systems in buildings or energy districts
• Research and pilot projects for resource-efficient energy systems

Key figures

• Remaining capacity (%): typically 60–80% when entering second-life use
• Cycle life: lower than new battery cells but sufficient for many stationary applications
• Cost per kWh: generally lower than new lithium-ion battery systems
• CO₂ savings: extended lifetime reduces environmental impact
• Certification & safety: necessary to ensure safe stationary operation

Summary

Second-life batteries enable the economically viable reuse of used batteries before recycling, extending their service life and reducing resource consumption.

They support the circular economy in the energy sector and can provide an attractive storage option for companies with strong sustainability goals, especially when slight reductions in performance or lifespan are acceptable.