Optimal control and safe operation, lifetime prediction and management are amongst the most important open questions in the field of battery energy storage systems and of particular importance for second-life battery storage systems. Customers currently lack confidence about the quality and remaining lifetime of second-life battery systems. In first-life BESS, cell parameters and expected lifetime are determined through expensive and often destructive lab tests executed on a subset of the battery cells. The test results are representative since all cells are new and behave in a similar way. This is not the case for second-life BESS, where each cell may have a different history and therefore a different remaining lifetime and cell parameters. A battery controlled without detailed knowledge of the state of the battery cells will not deliver its optimal value as both the operational limits and lifetime warranty need to be set in a conservative way, underusing its full commercial potential.
This project improves the way battery energy storage systems (BESS) are operated by bringing together the BMS, which traditionally performs battery pack state estimation, and the EMS, which controls the (dis)charging of the BESS, into iBEMS, an integrated battery & energy management system.
The iBEMS has access to all raw battery cell measurements normally only accessible by the BMS. The energy management and optimisation function of the iBEMS is performed leveraging the plethora of useful data from the battery cells. Traditionally, an EMS only sees the state of charge of the battery pack and this data would have been lost. The data is available in Octave’s battery cloud, which opens multiple improvements in operating the BESS, such as delivering an optimized service, building a digital twin of the cells, applying machine learning, extending the lifetime, improving monitoring and enabling predictive maintenance, all which are of particular importance for second-life battery systems.
