This report details the findings of the ARENA funded BMS-Inverter Hybrid Project, which aims to combine two central components in battery storage systems – the battery management system and the inverter – into a single solution.
Report extract
1. Executive summary
A crucial component of sustainable energy systems are battery solutions for individual homes, businesses, and the larger power grid. Any such installation requires not only a long-lived and cost-effective battery, but also an efficient and cost-effective battery inverter to convert the direct-current battery power into a useful alternating-current (AC) output. The cost of battery inverters today represents a significant hurdle for mass- adoption of battery storage and sustainable energy systems, and a significant uptake opportunity if reduced.
Relectrify is an Australian technology company that develops and supplies advanced battery management systems (BMS). These electronics sit inside the battery system and ensure safe, effective, and long-lived operation of battery systems. Due to the advanced capabilities of its lifetime- and capacity-enhancing BMS, Relectrify identified a unique opportunity to remove the separation between battery and inverter, and effectively co-utilise power electronics components for the benefit of both.
Relectrify’s BMS+Inverter is a set of electronics that can be connected to batteries and immediately make these AC-ready without needing an inverter, while unlocking additional battery lifetime. Grid-compliant AC waveforms are created by accurately orchestrating a vast number of individual cell voltage contributions within the battery and is suitable across residential, industrial and grid storage using either new or second- life batteries.
The key takeaways are as follows:
- Relectrify has successfully demonstrated both single-and three-phase prototype BMS+Inverter systems using second-life Nissan Leaf battery modules, in solutions rated up to 60kWh / 20kW.
- Preliminary testing demonstrated a round-cycle combined second-life battery and inverter efficiency in line with market-leading new battery products.
- Harmonics testing achieved power quality levels suitable for grid compliance.
- Relectrify has received notable customer interest in the BMS+Inverter and has secured follow-on demonstration projects on multiple continents.
