What Is Capacity — IEC 62133-2?
Capacity test is an experiment in which the amount of ampere-hours or watt-hours given by a fully charged battery is measured by discharging it to the cut-off voltage at a defined current and temperature.
Purpose of Capacity — IEC 62133-2
The purpose is to verify the declared nominal capacity, check batch-to-batch consistency and determine the initial reference for life tests.
Which Products Is Capacity — IEC 62133-2 Applied To?
- Lithium-ion cells
- Battery modules
- Electric vehicle battery packs
- Portable device batteries and power banks
- Energy storage systems
In Which Sectors Is Capacity — IEC 62133-2 Used?
Standards Related to Capacity — IEC 62133-2
- IEC 62133-2Safety in portable lithium cells and batteries test
Capacity — IEC 62133-2 Conditions
- Charge
- Manufacturer's declared charging method (typically CC-CV)
- Discharge current
- Rate defined by the standard or manufacturer (e.g. 0.2C, 1C)
- Kesme gerilimi
- Lower voltage limit declared by the manufacturer
- Temperature
- Reference temperature defined in the standard; Additionally, high and low temperature measurements may be requested
Equipment for Capacity — IEC 62133-2
- Battery testing system (inverter)
- temperature cabinet
- Data logging system
- Safety enclosure and gas evacuation
Sample Requirements for Capacity — IEC 62133-2
- The number of specimens is determined by the applicable standard
- Samples must complete the resting period required by the standard before testing.
- The manufacturer's charge/discharge limit values must be provided in writing
- BMS communication information is required for pack tests
Duration of Capacity — IEC 62133-2
A charge-discharge cycle takes several hours, depending on the discharge rate. If different temperature and current levels are desired, the total duration increases to several days.
Capacity — IEC 62133-2 Procedure
- 1The specimen is fully charged by the declared method.
- 2It is rested for the period required by the standard.
- 3It is discharged at the defined current down to the cut-off voltage.
- 4The given capacity (Ah) and energy (Wh) are calculated.
- 5If necessary, it is repeated at different temperature and current levels.
Capacity — IEC 62133-2 Acceptance Criteria
The acceptance criterion is generally that the measured capacity does not fall below a certain percentage of the declared nominal capacity. The percentage value is defined in the applicable standard or customer specification.
Evaluation of Results
Distribution between samples and temperature-dependent capacity change are evaluated together. Capacity testing provides an initial reference for life and safety testing.
Capacity — IEC 62133-2 Report
- Applied standard and revision
- Charge and discharge parameters
- Ambient temperature
- Measured capacity and energy values
- Voltage and temperature curves
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
- EU Battery Regulation
- UNECE R100 (vehicle)
- UN 38.3 (transport)
Batarya Testleri — What Does This Testing Field Cover?
The section below describes the field that the Capacity 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 Capacity — IEC 62133-2
Is capacity testing the same for cell, module and pack?
The method is similar but the parameters and security measures are different. At the pack level, the BMS must manage charge/discharge limits and receive data via communication.
Why is measurement required at different discharge currents?
The given capacity varies depending on the discharge current. Measurement at different rates shows the behavior of the battery in the actual usage profile.