MONITORING & METERING


A NEW APPROACH TO BATTERY SAFETY


Joe Holdsworth, founder and CEO of Metis Engineering, examines how advanced gas detection is transforming battery safety in EVs and energy storage


T


hermal runaway remains one of the most critical safety challenges facing the battery


industry. Whether in electric vehicles or grid- scale energy storage systems, the consequences of uncontrolled battery fires can be devastating, not just in terms of asset damage, but potentially in loss of life and public confidence in electrification technologies. The traditional approach to battery safety has centred on Battery Management Systems (BMS) that monitor cell voltage and temperature. Whilst these systems provide essential oversight, they suffer from a fundamental limitation: by the time temperature sensors register abnormal readings, a failing cell may already be approaching the point of no return. When a lithium-ion battery cell enters


thermal runaway, events escalate with alarming speed. Research consistently shows that once internal temperatures exceed 150-200˚C, self- accelerating chemical reactions become nearly impossible to arrest. Traditional temperature- based monitoring typically detects problems when cells have already reached 100-150˚C internally, offering minimal time for intervention. This timing deficit has real-world implications.


A University of Bath Formula Student team experienced this during pre-competition testing when their battery pack’s conventional temperature sensors showed normal readings even as one cell was actively venting gas. Without advanced detection technology, thermal modelling suggested full thermal runaway would have occurred within 45-60 seconds, potentially during an on-track test with a driver in the vehicle.


VOC DETECTION: A DIFFERENT APPROACH Advanced battery safety sensors like Metis Engineering’s Cell Guard address this timing problem by detecting an earlier precursor: volatile organic compounds (VOCs) released during cell venting. Studies by Sandia National Laboratories and research published in the Journal of the


Electrochemical Society confirm that VOC emissions represent one of the earliest detectable signs of cell failure, often appearing several minutes before significant temperature rises. Beyond VOCs,


Cell Guard provides continuous monitoring of critical environmental conditions including moisture ingress, dew point, air temperature, pressure changes, and hydrogen (an indicator of both electrolysis from moisture ingress and later-stage thermal runaway), with an optional accelerometer capturing shock loading data from impacts or collisions. When a battery cell experiences internal stress, whether from manufacturing defects, mechanical


“Comprehensive battery safety requires monitoring multiple parameters simultaneously”


damage, or operational abuse, the electrolyte begins breaking down before temperatures spike. This decomposition releases gases including ethylene carbonate and diethyl carbonate, which can be detected at very low concentrations. By monitoring VOC levels inside the battery


enclosure, operators gain a crucial intervention window to identify problems during the initial stages of cell distress, when containment and shutdown procedures may still prevent escalation and the vehicle can be evacuated safely. Independent testing by Sandia National


Joe Holdsworth 30


Laboratories provides compelling evidence of the effectiveness of gas-based detection. In comparative testing against hydrogen-only sensors and higher-cost systems designed primarily for energy storage applications, Cell Guard detected thermal events in under 60 seconds from initial cell venting, up to seven minutes faster than competing technologies. This speed advantage translates into actionable safety margins. With early VOC detection,


ENERGY & SUSTAINABILITY SOLUTIONS - Spring 2026


battery management systems can execute complete system shutdowns, activate enhanced cooling, alert occupants or operators, and isolate affected modules, all before thermal runaway becomes inevitable.


EARLY DETECTION In electric vehicles, early thermal runaway detection enables driver warnings and automated safety responses whilst vehicles remain operational, allowing for safe stopping and evacuation. The compact form factor of modern VOC sensors permits installation inside battery packs without disrupting existing architecture, whilst CAN bus integration enables seamless communication with vehicle systems. For grid-scale battery energy storage systems, the stakes involve larger energy capacities and often more constrained emergency


response capabilities.


A single failing cell in a multi-megawatt installation can threaten substantial assets. Early detection becomes even more critical in applications like remote renewable energy


installations or marine vessels,


where firefighting resources may be hours away. Comprehensive battery safety requires monitoring


multiple parameters simultaneously. Modern sensor systems complement VOC detection with hydrogen sensing, humidity and dew point tracking, and temperature monitoring. This multi-parameter approach provides redundancy, hydrogen detection serves as a secondary check when ambient VOC levels are already elevated, whilst moisture monitoring identifies water ingress that could cause short circuits.


THE PATH FORWARD As battery installations proliferate across transport and energy sectors, safety systems must evolve beyond reactive temperature monitoring toward predictive, chemistry-specific detection. The integration of advanced gas sensing technology represents a practical step toward this goal, one supported by independent validation and increasingly recognised as essential by operators prioritising system safety and reliability. For facility managers, fleet operators and energy storage system integrators, the question is no longer whether early detection technology is necessary, but rather how quickly it can be implemented across existing and planned battery installations. The technology exists. The validation is established. What remains is deployment at the scale required to match the rapid growth of battery-dependent infrastructure across the energy system.


Metis Engineering https://metisengineering.com/


www.essmag.co.uk


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