What Is Thermal Runaway — IEC 62133-2?
The thermal runaway test is a test in which an uncontrolled exothermic reaction is deliberately initiated in a cell, measuring the energy, temperature and gases released. Triggering is done by heating, overcharge or internal short circuit.
Purpose of Thermal Runaway — IEC 62133-2
The purpose is to characterise the energy released when thermal runaway occurs and to verify the warning and protection responses of the battery system.
Which Products Is Thermal Runaway — IEC 62133-2 Applied To?
- Lithium-ion cells
- Electric vehicle battery modules and packs
- Energy storage systems
In Which Sectors Is Thermal Runaway — IEC 62133-2 Used?
Standards Related to Thermal Runaway — IEC 62133-2
- IEC 62133-2Safety in portable lithium cells and batteries test
Thermal Runaway — IEC 62133-2 Conditions
- Triggering method
- Surface heater, overcharge or nail penetration; defined in the specification
- Measurement
- Multi-point temperature, voltage, gas composition and, if required, heat flux
- Termination
- Temperatures returning to ambient level
- Safety
- Explosion-protected room, gas venting and extinguishing are mandatory
Equipment for Thermal Runaway — IEC 62133-2
- Explosion-protected test room
- Surface heater or triggering rig
- High-sample-rate temperature recording
- Gas analysis system (FTIR or GC)
- Thermal camera and high-speed video
Sample Requirements for Thermal Runaway — IEC 62133-2
- The specimen is taken into the test fully charged
- The position of the cell to be triggered must be determined
- The test is single-use and high-risk
- The cell chemistry and energy content must be known
Duration of Thermal Runaway — IEC 62133-2
The event lasts minutes; together with preparation, observation, cooling and gas analysis, several days are planned.
Thermal Runaway — IEC 62133-2 Procedure
- 1The specimen is prepared, and thermocouples and gas-sampling lines are set up.
- 2The specimen is placed in the explosion-protected room.
- 3Thermal runaway is initiated by applying the triggering method.
- 4Temperature, voltage and gas data are recorded at high speed.
- 5Monitoring continues until the event is complete and temperatures drop.
- 6Mass loss, residue and gas composition are analysed.
Thermal Runaway — IEC 62133-2 Acceptance Criteria
This test is generally for characterisation purposes. If a criterion is applied, it is defined in the specification as propagation not spreading to neighbouring cells, or the system issuing a warning.
Evaluation of Results
Peak temperature, rate of temperature rise, and the quantity and composition of released gas are evaluated. The results serve as input to the propagation test.
Thermal Runaway — IEC 62133-2 Report
- Applied specification and triggering method
- Cell chemistry, energy content and state of charge
- Temperature and voltage records
- Gas composition and quantity
- Mass loss, video and thermal imagery
Accreditation
EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.
Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.
Scope and authorisationsRelated Regulations
- UNECE R100 Part II
- GB 38031
- EU Battery Regulation
Batarya Testleri — What Does This Testing Field Cover?
The section below describes the field that the Thermal Runaway test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.
Battery testing answers three separate questions, each with its own body of standards: can the battery be transported, is it safe in use, does it deliver the declared performance? These three questions are often confused with one another, and the confusion has commercial consequences — a market cannot be entered with a transport report, and a shipment cannot be made with a product safety report.
On the transport side, UN 38.3 is a mandatory gate; a battery without that evidence cannot be shipped. On the safety side the application determines what applies: IEC 62133-2 for portable products, IEC 62619 and IEC 63056 for industrial and energy storage applications, UNECE R100, UL 2580 and ISO 6469 for electric vehicles. On the performance side, capacity, internal resistance, cycle life, self-discharge, charge acceptance and temperature-dependent behaviour are measured.
The distinction of LEVEL is essential in this family and is the subject that causes the most argument in the supply chain. Cell, module and pack are assessed separately; a certificate obtained for a cell does not demonstrate the conformity of the pack. Alongside the cells, the behaviour of the pack is determined by the battery management system, the cooling design, the mechanical structure, the interconnection arrangement and insulation coordination. Putting the cell supplier's report into the pack file is a common but inadequate approach.
Thermal runaway and its propagation are the most critical subject in the field. A lithium cell may enter a self-sustaining chemical reaction when damaged or overheated; at that point removing the heat from outside is usually not possible. Modern standards therefore treat thermal runaway of a single cell as an UNAVOIDABLE fault scenario and change the question: does the event propagate to neighbouring cells, what does it release outside the pack, and how much time is left for the user to escape?
In this field the battery management system is assessed not as an electronic board but as a SAFETY FUNCTION. It is shown that overcharge, overdischarge, overcurrent and overtemperature protections actually operate, that the system falls to the safe side in a fault, and that its software has been verified. In industrial and vehicle applications this assessment is tied to functional safety frameworks.
The regulatory side is becoming rapidly more demanding. Battery Regulation (EU) 2023/1542 goes beyond safety and introduces obligations for carbon footprint declaration, recovered content ratio, durability and capacity declaration, the battery passport, and removability for portable batteries. This takes the scope of testing beyond classical safety tests.
Method groups in this field
Electrical abuse
Overcharge, overdischarge, external short circuit, forced discharge and unbalanced charging. This is where it is seen whether the protection circuits actually work.
Mechanical abuse
Vibration, shock, crush, penetration, free fall and tipping. It is monitored whether internal short circuit conditions arise.
Thermal tests
Temperature cycling, thermal shock, high temperature storage, fire exposure and thermal runaway propagation.
Environmental tests
Humidity, low pressure, salt spray and, where required, immersion; these come to the fore in vehicle and outdoor applications.
Performance measurements
Capacity, energy and power, internal resistance, efficiency, cycle life, calendar life and temperature-dependent behaviour.
BMS verification
Verification of protection thresholds, the cell balancing function, communications and fault response.
Commonly confused in this field
- UN 38.3 is not a product safety certificate; it only demonstrates transport conformity.
- A cell certificate does not demonstrate pack conformity. The pack is assessed separately with its own architecture.
- Two packs built from the same cell give different results; cooling, interconnection and mechanical structure are decisive.
- A performance test is not a safety test. A cycle life report does not satisfy safety requirements.
- For an electric vehicle battery, a UL 2580 report and UNECE R100 approval are not the same thing; one is a standards assessment, the other a type approval regime.
- A vehicle battery moved into a second-life application enters a new usage profile; the earlier assessment does not carry over directly.
Which decisions these results support
- Transport conformity and the test summary for shipment
- Product safety declaration and market access
- Performance, durability and carbon footprint declarations under the Battery Regulation
- Assessing the impact of a cell supplier or BMS change
- Site acceptance processes for an energy storage system
Related Tests
Frequently Asked Questions About Thermal Runaway — IEC 62133-2
According to which standard is Thermal Runaway made?
Thermal Runaway is executed in scope UNECE R100, UL 2580, GB 38031, SAE J2464 and IEC 62133-2. The limit values and acceptance criteria to be applied are defined in the product standard; The version valid for your product is confirmed in writing at the offer stage.
Which products does Thermal Runaway apply to?
Mainly applied to Lithium-ion cells, Electric vehicle battery modules and packs and Energy storage systems. Whether your product is included in the scope is determined by examining its technical specifications and intended use.
Under what conditions is Thermal Runaway done?
The determining parameters are: Triggering method — Surface heater, overcharge or nail penetration; defined in the specification, Measurement — Multi-point temperature, voltage, gas composition and, if required, heat flux and Termination — Temperatures returning to ambient level. The full terms are in the "Test Conditions" section on the page and vary depending on the product standard.
What kind of sample is needed for Thermal Runaway?
The specimen is taken into the test fully charged, The position of the cell to be triggered must be determined and The test is single-use and high-risk. The number of samples is determined according to the product standard and the scope to be reported.
How long does Thermal Runaway take?
The event lasts minutes; together with preparation, observation, cooling and gas analysis, several days are planned. This duration belongs to the experiment itself; sample preparation, queuing and reporting are also evaluated. A realistic schedule for your product is given in the offer.
What is the Thermal Runaway result called "appropriate"?
This test is generally for characterisation purposes. If a criterion is applied, it is defined in the specification as propagation not spreading to neighbouring cells, or the system issuing a warning.