There remains a stigma around second-life batteries that, due to degradation, the batteries present more of a risk.
While it would be unethical to claim that there is no risk from second-life batteries, advances in battery management and rigorous safety protocols are demonstrating the potential for second-life batteries to be deployed safely and effectively.
Firstly, there is now the beginnings of academic research into this topic. A recent study by MEET – Münster Electrochemical Energy Technology at the University of Münster found that battery cell safety increases during ageing, including into second life. Scientists recorded safety improvements all the way from 91% to 63% state of health, where the experiment concluded. Of course, this does not definitively prove that second-life batteries are safe, but it is pointing in that direction.
Secondly, at Connected Energy we have one of the largest and most unique data sets on second-life batteries in the world. We pioneered using second-life batteries in battery energy storage systems (BESS) and have been working with second life since 2010, meaning we have 15 years’ worth of data in this field.
Traditionally, battery and automotive OEMs have focussed their performance analysis on battery capacity from 100% down to 70% at pack level. This is because it is the important operating range for EV performance. Because we are exclusively using second-life EV batteries, we are typically dealing with battery capacity from 80% downwards. This unique combination of experience and data has enabled us to develop new ways to safely optimise second-life batteries as stationary energy storage assets.
