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BESS Thermal Runaway PreventionHow dQ/dV Analysis Catches What SCADA Misses

LFP batteries have flat voltage curves that hide degradation from standard monitoring. Physics-informed dQ/dV differentiation reveals lithium plating and capacity fade weeks before thermal runaway — the gap between SCADA alerts and forensic detection.

February 10, 2026
5 min read
Lee Wen Jie
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BESS Thermal Runaway Prevention: How dQ/dV Analysis Catches What SCADA Misses

Why Standard SCADA Monitoring Fails for LFP Battery Safety

The global Battery Energy Storage System (BESS) market is projected to exceed 500 GWh by 2030. Yet the safety monitoring infrastructure deployed at most sites hasn't evolved beyond basic threshold alarms set during commissioning.

The fundamental problem: LFP (Lithium Iron Phosphate) batteries have an inherently flat voltage curve. Between 20% and 80% State of Charge, the voltage barely moves — typically less than 200mV across the entire operating range. This flat characteristic, which makes LFP excellent for grid applications, also makes it nearly invisible to traditional voltage-based monitoring.

The Detection Gap

Consider a typical 50MW/100MWh BESS installation monitored by a standard SCADA system:

  • Temperature sensors: Trigger at fixed thresholds (typically 45°C cell surface). By the time surface temperature rises, internal cell temperature may be 20-30°C higher. The thermal runaway cascade has already initiated.
  • Voltage monitoring: Checks cell/module voltage against min/max bounds. On an LFP cell, a 3mV deviation at the module level could represent a 15% capacity fade — but it falls within "normal" SCADA tolerance bands.
  • SOC estimation: Usually Coulomb counting with periodic OCV recalibration. Drift accumulates. After 6 months without recalibration, SOC estimates can be off by 5-10%.

The result: The most dangerous degradation modes — lithium plating, internal short circuits, and electrolyte decomposition — produce signals that are below SCADA detection thresholds for weeks or months before catastrophic failure.

What is dQ/dV Analysis?

Differential capacity analysis (dQ/dV) is a technique borrowed from electrochemistry research. Instead of monitoring absolute voltage, we compute the derivative of charge with respect to voltage — essentially asking: "How much charge does the battery accept per unit of voltage change?"

In a healthy LFP cell, the dQ/dV curve shows characteristic peaks corresponding to phase transitions in the cathode material. As the cell degrades:

  1. Peak shifting: The voltage at which phase transitions occur shifts, indicating loss of active lithium
  2. Peak broadening: Wider peaks indicate increased internal resistance and heterogeneous degradation
  3. Peak height reduction: Lower peaks reveal capacity fade at the material level
  4. New peak emergence: Additional peaks can indicate lithium plating or parasitic side reactions

These changes are detectable weeks to months before they manifest as measurable capacity loss or temperature anomalies in SCADA data.

Why This Requires HFT-Grade Signal Processing

The challenge isn't the math — it's the data rate and noise floor. Grid-scale BESS telemetry arrives at rates of 1-10Hz per cell, with measurement noise, communication jitter, and environmental interference. Computing reliable dQ/dV curves from this data requires:

  • High-frequency sampling alignment: Synchronizing voltage and current measurements across thousands of cells with sub-millisecond precision
  • Noise filtering without signal destruction: Aggressive smoothing kills the subtle peak features. Too little smoothing produces meaningless noise. The sweet spot requires adaptive windowing based on the current operating regime.
  • Real-time processing: A 100MWh facility may have 50,000+ individual cells. Processing dQ/dV for each cell in real-time, while maintaining historical baselines, requires the kind of high-concurrency architecture used in quantitative trading.

At Oxaide, we built our Horizon engine on the same Rust-based signal processing architecture used for sub-millisecond capital markets analysis. Zero garbage collection. Deterministic latency. Memory-safe by compilation guarantee.

The Forensic Audit Approach

Our methodology follows a two-stage model:

Stage 1: Oxaide Verify (Diagnostic)

We take your historical BESS telemetry data — typically CSV exports from your BMS or SCADA historian — and run a forensic audit. The output is a litigation-grade PDF report identifying:

  • Cells or modules showing early-stage degradation patterns
  • Estimated capacity fade vs. warranty specifications
  • Yield gap quantification (how much revenue is being lost to undetected inefficiency)
  • Risk classification for thermal events

Stage 2: Oxaide Horizon (Permanent Safety Layer)

Based on the diagnostic findings, we deploy a compiled Rust binary to your edge gateway. This runs continuously, processing live telemetry and detecting anomalies in real-time. No cloud dependency. No data egress. Air-gapped deployment available.

The Economics

For a 50MW BESS facility with a 15-year operating horizon:

  • 1% undetected yield gap = approximately S$500k in lost revenue over the asset lifetime
  • One thermal runaway event = S$2-10M in direct losses plus insurance premium increases
  • Oxaide Horizon pilot license = S$35,000 per site

The ROI case is straightforward: detecting a single anomaly that prevents one yield-reducing event pays for the system many times over.

Conclusion

The BESS industry is at an inflection point. As installations scale from pilot projects to grid-critical infrastructure, the gap between "monitoring" (SCADA threshold alerts) and "safety" (physics-informed forensic detection) will determine which operators avoid catastrophic losses.

Standard monitoring tells you when something has already gone wrong. Physics-informed dQ/dV analysis tells you when something is going wrong — while there's still time to act.


Want to see what your BESS telemetry reveals? Request a Verify forensic audit — we analyze your data and show you exactly what standard monitoring is missing.

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