UL 9540A has become the reference method for understanding what happens when a lithium-ion cell goes into thermal runaway inside an energy storage system. Its cell- and unit-level tests call for heat release measurement on a large scale: vent gases and flames from a failing cell or module are captured under a hood and measured by oxygen-consumption calorimetry, the same principle as the cone calorimeter scaled up to battery dimensions.
How the Heat Release Calorimetry for UL 9540A works
The specimen - from a single cell at cell level to a complete unit at unit level - is driven into thermal runaway under an exhaust hood. All combustion products are collected, and heat release rate is calculated from oxygen depletion in the exhaust stream, together with vent gas and temperature data the method requires. The Motis UL 9540A configuration applies this calorimetry arrangement to the cell and unit level tests described in the method.
Key specifications
| Standard | UL 9540A - Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems |
|---|---|
| Test levels covered | Cell level and unit level heat release measurement |
| Principle | Oxygen-consumption calorimetry under a collection hood, scaled from bench calorimetry to battery specimens |
What the test reports
- Heat release rate during thermal runaway
- Total heat released
- Thermal runaway propagation behaviour at unit level (as set out in the method)
Applications
Battery manufacturers, energy storage integrators and test houses use UL 9540A data for installation approvals and for the reports that fire codes in North America ask for. See also our battery fire testing category, which covers cell abuse, fire exposure and propagation instruments.
Frequently asked questions
Which standard should I order against?
Order against the standard your reports must cite. The instrument platform is shared across the listed standards, but fixtures, software templates and calibration routines differ, so name the standard (and its year) in your inquiry and the configuration will be matched to it.
Do you supply the whole UL 9540A setup?
UL 9540A involves several test levels and several instrument types. This page covers the heat release calorimetry side. Describe the level you need to run - cell, module, unit or installation - in your inquiry and we will map the equipment list to it.
Is this a pass/fail test?
UL 9540A is a test method that generates data; how the data are used is decided by the authority having jurisdiction and the applicable installation codes. The instrument's job is to produce the heat release record the method defines.
Configuration, installation and support
Every Heat Release Calorimetry for UL 9540A is supplied as a configured system, not a bare instrument: the test chamber or frame, the burner or heater assemblies named in the method, the measurement chain and the control software with the report templates for UL 9540A. Before quotation we confirm the installation conditions with you - floor loading and ceiling height for large rigs, exhaust and extraction routes, gas and fuel services, and power supply - because a fire test instrument only produces defensible data when the room around it is right. Commissioning covers assembly, calibration of the measurement chain against the method's own checks, and training of your operators on running the test and maintaining the apparatus. Spare ignition parts, thermocouples and other consumables for the first period of operation can be included in the supply, and the instrument is supported with calibration and maintenance services after installation.
What to include in your inquiry
To quote the Heat Release Calorimetry for UL 9540A correctly the first time, send: the standard and edition you will test to (UL 9540A); the materials or products you will test and their sizes; the configuration options you already know you need; and the destination laboratory's location and available services. If you are building a new fire laboratory rather than adding one instrument, say so - this apparatus is often planned together with the other instruments in its category, and a combined layout and exhaust plan is cheaper than three separate ones.