The idea in 18 seconds
Why gas comes first
Thermal runaway rarely starts without a sign. Gas is one of the earliest — published numbers:
- 5–20 minutes: off-gassing precedes thermal runaway by roughly 5 to 20 minutes, according to FM.
- 7.8 minutes: in Sandia cell tests, FTIR saw the first gas signal 7.8 minutes before thermal runaway (2024).
- Electrolyte vapour first: at the first vent, DMC, EC and HF were among the first species detected; DMC alone made up 12–42 vol% of the vent gas (Lin & Ezekoye, 2025).
- Hydrogen often late: in installation tests, electrolyte (VOC) sensors triggered first, while common hydrogen and combustible-gas detectors often only confirmed that thermal runaway had started (Sandia, 2021).
- Early life matters: 72% of BESS failures with a known age happened during construction, commissioning or the first two years of operation (EPRI).
// The point of early warning is choice: flag one module while there is still time to isolate it, instead of losing a container or a car.
Where codes are heading
Codes and approvals are starting to name the precursor gas. Summaries are informational, not legal advice; codes change, so verify the current text before acting.
Dec 2023
NL PGS 37-1, measure M32: fixed CO detection at BESS sites, with actions at 10 / 20 / 120 ppm
Dec 2024
First approval under FM 6540, the FM standard for solvent-vapour (off-gas) detectors
Jul 2025
Austin Fire Code 2024 §1207.6.5: a thermal-runaway detector sensing electrolyte vapour, listed to UL 2075, for ESS above 20 kWh
9 Sep 2025
NFPA 855:2026 published; off-gas named as a precursor for thermal-runaway propagation prevention
1 Sep 2027
UN R100.05 applies to new EV types: occupants warned 5 minutes before a hazardous situation from thermal propagation
2028 (expected)
NL Bal amendment expected to make PGS 37-1 legally binding for BESS
What we are researching
What we are trying to learn — not what we sell.
Our base is gas sensing R&D on our own NDIR products, plus research on photonic (PIC) gas sensing. For batteries we are screening three questions with people who run, design and insure battery systems:
- Where an early gas signal would change a decision — at rack, container or pack level, and who acts on it.
- Which gas is worth sensing for that decision, given that electrolyte vapour is the earliest selective marker in the published tests.
- Which optical technology fits. Optical electrolyte-vapour sensing already exists in mid-infrared NDIR form. Whether a chip-scale photonic sensor can do the same job is an open research question for us.
// Concept in research. No battery product, no field data, no claims on detection levels. The animation above is a concept visual of the idea, not a design.
Questions engineers ask
Is this a Tremon product?
No. This is application research: we are screening where gas-based early warning of Li-ion thermal runaway could help, through interviews with BESS, EV-pack and battery-safety experts. We do not sell a battery off-gas detector.
Which gas comes first?
Published tests point to electrolyte solvent vapour. In abuse tests DMC, EC and HF were among the first species detected at the vent (Lin & Ezekoye 2025), and in installation tests electrolyte (VOC) sensors triggered first, while common hydrogen and combustible-gas detectors often only confirmed that thermal runaway had started (Sandia, 2021).
Can a photonic chip sense electrolyte vapour?
That is an open research question for us. Optical electrolyte-vapour sensing already exists today in mid-infrared NDIR form; whether a chip-scale photonic sensor can do the same job is one of the things we are investigating, together with our NDIR gas-sensing R&D.
Collaborate with us
// thermal runaway · research collaboration
Let's research this together
We are screening where gas-based early warning could help battery systems isolate one module instead of the whole site or car. We want to learn this with the people who build, run, test and insure them.
// who we look for
- BESS owners, operators and integrators
- EV and e-mobility battery-pack engineers
- Battery test and certification labs
- Fire-safety engineers and insurers
- University and institute groups working on battery safety
// what collaboration means
- Expert interview — 30 minutes on how you handle battery off-gas and thermal runaway today, and where a new kind of sensor would — or would not — help.
- Feasibility study or pilot — We scope your use case together — your gas, site or system — and test whether the concept fits. A pilot follows once there is hardware to put on site.
- Joint research or grant consortium — Partner with us in a joint research project or an EU or national grant consortium on Li-ion off-gas and thermal-runaway early warning.
// research stage · not a product · [email protected]