SOC Corrections Boost Profitability

The Challenge  

Profitability in energy storage systems hinges on many factors, but two of the most important are availability and state of charge (SOC) estimation accuracy. Unfortunately, a European-based operator was having problems with both. Their trading strategies depended heavily on SOC readings from the battery management system (BMS), but the data was wildly inconsistent—at times off by as much as 50%.

These inaccuracies had far-reaching consequences. Unreliable SOC data meant missed trading opportunities and penalties for failing to meet contractual obligations, directly reducing revenue potential. At the same time, prolonged errors in SOC estimation put the operator at risk of breaching battery warranties, which could lead to expensive repairs or replacements. Efficiency also suffered, as the operator struggled to recalibrate at opportune moments resulting in unplanned downtime during high-value events.

Together, these issues posed a significant threat to the operator’s bottom line, jeopardizing the financial sustainability of their energy storage system.

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Solution and Approach

Determined to uncover the root cause of the inaccuracies and find a solution, the operator brought in ACCURE Battery Intelligence. ACCURE began by ingesting existing data from the operator’s energy storage system and incorporated insights from similar systems around the world. This created a detailed picture of the system’s performance and laid the foundation for a deeper analysis.

Next, ACCURE applied a specialized state-of-charge (SOC) estimation model tailored to Lithium Iron Phosphate (LFP) batteries. This technique pinpointed the differences between the SOC reported by the system’s Battery Management System (BMS) and the system's actual SOC. To address these discrepancies, ACCURE developed a custom correction model designed to recalibrate and refine the SOC estimates, eliminating the errors.

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Results and Benefits

An early SOC detection system was implemented to identify error build-ups early, enabling the operator to schedule recalibrations during low-value time slots. Now, continuous SOC calculations have minimized errors to a +/- 3% margin, a huge improvement from the previous inaccuracies of up to 50%.

More than just a technical fix, these changes have empowered the operator to regain control over their trading strategies and make smarter, data-informed decisions. By focusing on understanding and resolving the root issue, the operator achieved efficiency and reliability that underscores the role of accurate SOC readings in driving revenue.