Imbalance and ICA Monitoring for Multiple Battery-Electrolyser Cells in Series

This paper investigates imbalance and the application of Incremental Capacity Analysis (ICA) in monitoring lead-acid battery-electrolysers. These are single devices which function as both batteries and electrolysers. The study examines whether traditional monitoring and balancing strategies used in lithium-ion batteries are applicable to battery-electrolysers in series configurations. Findings suggest that cell balancing may not be necessary for systems with low levels of degradation as cell voltages align and electrolysis helps to balance cells further. ICA is employed to generate Incremental Capacity (IC) curves, which are reportedly used to detect subtle changes in battery behavior indicative of degradation. The proportional change method is applied to estimate state of health (SOH), yielding estimations within 7.9% of the actual measured SOH, indicating the potential of ICA as a tool for monitoring health in battery-electrolysers. However, the ICA only works when the battery-electrolyser is functioning as a battery. These findings suggest that, although cell monitoring and active balancing may not be required for minor degradation, the hardware could be useful for long term ICA tracking of degradation.