What Is Charge/Discharge — UN 38.3?
The charge/discharge test is the basic performance test in which the battery is charged by the declared method and discharged at a defined current, while voltage, current, temperature and the energy delivered are measured.
Purpose of Charge/Discharge — UN 38.3
The purpose is to verify that the battery can deliver energy and power appropriate to its use profile, and to determine its efficiency and temperature behaviour.
Which Products Is Charge/Discharge — UN 38.3 Applied To?
- Lithium-ion cell, module and pack
- Portable device batteries
- Electric vehicle batteries
- Energy storage systems
In Which Sectors Is Charge/Discharge — UN 38.3 Used?
Standards Related to Charge/Discharge — UN 38.3
- UN 38.3Transport safety tests on lithium batteries test
Charge/Discharge — UN 38.3 Conditions
- Charging method
- CC-CV current and voltage values declared by the manufacturer
- Discharge current
- Rate defined in the specification (e.g. 0.2C, 1C, 2C)
- Cut-off voltages
- Upper and lower limits declared by the manufacturer
- Temperature
- Reference temperature and, if required, high/low temperature steps
Equipment for Charge/Discharge — UN 38.3
- Battery test system
- temperature cabinet
- Multi-channel data logging
- Safety enclosure
Sample Requirements for Charge/Discharge — UN 38.3
- The number of specimens is set out in the specification
- The declared charge/discharge limits must be provided in writing
- Specimens must be rested before testing
- BMS communication information is required for pack tests
Duration of Charge/Discharge — UN 38.3
A single cycle takes a few hours depending on the discharge rate. If multiple current and temperature steps are requested, the total duration extends to days.
Charge/Discharge — UN 38.3 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 delivered capacity, energy and efficiency are calculated.
- 5The test is repeated at different current and temperature steps.
Charge/Discharge — UN 38.3 Acceptance Criteria
The acceptance criterion is that the capacity and energy do not fall below a specified percentage of the values declared in the specification.
Evaluation of Results
The voltage curve, temperature rise and cycle efficiency are evaluated together. A greater-than-expected temperature rise at high current indicates a thermal design issue.
Charge/Discharge — UN 38.3 Report
- Standard applied
- Charge and discharge parameters
- Ambient temperature and steps
- Capacity, energy and efficiency 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
Batarya Testleri — What Does This Testing Field Cover?
The section below describes the field that the Charge/Discharge 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 Charge/Discharge — UN 38.3
According to which standard is Charge/Discharge made?
Charge/Discharge is executed in scope IEC 62133-2, IEC 62619, ISO 12405, UL 2580, UNECE R100 and UN 38.3. 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 Charge/Discharge apply to?
Mainly applied to Lithium-ion cell, module and pack, Portable device batteries, Electric vehicle batteries 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 Charge/Discharge done?
The determining parameters are: Charging method — CC-CV current and voltage values declared by the manufacturer, Discharge current — Rate defined in the specification (e.g. 0.2C, 1C, 2C) and Cut-off voltages — Upper and lower limits declared by the manufacturer. 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 Charge/Discharge?
The number of specimens is set out in the specification, The declared charge/discharge limits must be provided in writing and Specimens must be rested before testing. The number of samples is determined according to the product standard and the scope to be reported.
How long does Charge/Discharge take?
A single cycle takes a few hours depending on the discharge rate. If multiple current and temperature steps are requested, the total duration extends to days. 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 Charge/Discharge result called "appropriate"?
The acceptance criterion is that the capacity and energy do not fall below a specified percentage of the values declared in the specification.