When comparing lithium battery cells from different manufacturers, capacity, cycle life, internal resistance, and low-temperature performance are some of the most important parameters.
But how can buyers determine whether the performance data from different suppliers is comparable?
IEC 61960 provides a standardized framework for evaluating the performance of secondary lithium cells and batteries for portable applications. It gives purchasers and users a consistent set of criteria for comparing products from different manufacturers.
IEC 61960 is essentially a performance standard. It is complementary to safety standards such as IEC 62133-2.
In simple terms:
IEC 62133-2 asks: “Is the battery safe?”
IEC 61960 asks: “How well does the battery perform?”
1. What Is IEC 61960?
IEC 61960 is an international standard published by the International Electrotechnical Commission (IEC) for secondary lithium cells and batteries used in portable applications.
The standard specifies performance tests, designations, markings, dimensions, and other requirements. Its purpose is to provide purchasers and users with standardized criteria for evaluating the performance of lithium cells and batteries from different manufacturers.
It is particularly useful when comparing:
- Rated capacity
- Discharge performance
- Cycle life
- Internal resistance
- Temperature performance
- Charge retention
- Physical dimensions and markings
This makes IEC 61960 useful for cell selection, supplier evaluation, product development, and quality control.
2. How Is the IEC 61960 Standard Structured?
The previous IEC 61960:2011 edition was withdrawn in April 2020 and replaced by separate standards covering different types of secondary lithium cells and batteries.
The current structure includes:
| Part | Standard | Main Scope | Status |
|---|---|---|---|
| Part 3 | IEC 61960-3:2017 | Prismatic and cylindrical secondary lithium cells and batteries | Current |
| Part 4 | IEC 61960-4:2024 | Coin secondary lithium cells and batteries | Current |
IEC 61960-3:2017
IEC 61960-3 covers prismatic and cylindrical secondary lithium cells and batteries for portable applications. Typical portable applications include handheld, transportable, and movable equipment.
This includes many common lithium-ion cell formats used in portable products, such as cylindrical cells and prismatic or laminate-film cells.
IEC 61960-4:2024
IEC 61960-4 covers coin-type secondary lithium cells and batteries, including applications such as watches and backup power applications. The current 2024 edition replaced the 2020 edition.
3. IEC 61960 vs. IEC 62133-2: Performance vs. Safety
IEC 61960 and IEC 62133-2 serve different purposes.
| Comparison | IEC 61960 | IEC 62133-2 |
|---|---|---|
| Main Question | How well does the battery perform? | Is the battery safe? |
| Main Focus | Capacity, discharge performance, cycle life, internal resistance, etc. | Electrical, mechanical, and abuse-related safety |
| Typical Use | Performance comparison, supplier evaluation, quality control | Safety compliance and market requirements |
| Purpose | Verify and compare performance | Evaluate safety under specified conditions |
| Relationship | Performance | Safety |
In other words:
IEC 62133-2 focuses on battery safety, while IEC 61960 focuses on battery performance.
They should not be treated as substitutes. Depending on the product and target market, both performance evaluation and safety compliance may be required.
4. Key IEC 61960-3 Performance Tests
IEC 61960-3:2017 specifies performance tests for prismatic and cylindrical secondary lithium cells and batteries used in portable applications.
The main performance areas include the following.
4.1 Rated Capacity Test
The rated capacity test evaluates whether the battery can deliver the capacity declared by the manufacturer under the specified test conditions.
After standard charging, the cell or battery is discharged under the specified conditions at a controlled ambient temperature until the specified end-of-discharge voltage is reached.
The measured discharge capacity is then compared with the declared rated capacity.
This is one of the most important tests for verifying whether the battery’s actual capacity matches its specification.
4.2 Discharge Performance at Different Temperatures
Battery performance changes significantly with temperature.
IEC 61960-3 includes discharge performance evaluation under specified temperature conditions. This helps determine how much usable capacity the battery can deliver in different environments.
Low-temperature testing is particularly important for applications used in:
- Outdoor equipment
- Portable electronics
- Industrial equipment
- Cold-climate applications
- Battery-powered devices exposed to seasonal temperature changes
A battery that performs well at room temperature may deliver significantly less usable capacity at low temperatures.
Therefore, rated capacity alone does not provide a complete picture of real-world battery performance.
4.3 Charge Retention and Recovery
Charge retention testing evaluates how well a battery maintains its stored charge after being left under specified storage conditions.
After storage, the remaining capacity is measured. The battery may then be recharged and tested again to evaluate its recovery capacity.
This type of test is useful for evaluating battery behavior during:
- Warehousing
- Transportation
- Product storage
- Shelf life
It is particularly relevant when batteries may remain unused for extended periods before being installed into the final product.
4.4 Cycle Life
Cycle-life testing evaluates how battery capacity changes after repeated charge and discharge cycles under specified conditions.
Cycle life is one of the most important indicators of the battery’s long-term performance.
However, cycle-life data should always be interpreted together with the test conditions, including:
- Charge/discharge current
- DOD
- Charge voltage
- Discharge cutoff voltage
- Ambient temperature
- End-of-life criterion
A statement such as “500 cycles” is incomplete unless the testing conditions are also specified.
IEC 61960-3:2017 also includes an accelerated cycle-life test procedure intended to reduce testing time under specified conditions.
4.5 Internal Resistance
Internal resistance is another important battery performance parameter.
IEC 61960-3 includes internal resistance measurement under specified test conditions.
A lower internal resistance generally means lower voltage drop and lower heat generation under the same operating conditions, although the actual relationship depends on the battery design, temperature, SOC, and measurement method.
For battery sourcing and quality control, internal resistance can be useful for:
- Cell sorting
- Batch consistency evaluation
- Power capability assessment
- Detecting abnormal cells
- Comparing suppliers
For more information about ACIR and DCIR, see our related article:
ACIR vs. DCIR: Why Do Battery Resistance Measurements Differ by Several Milliohms?
4.6 ESD and Battery Protection
For battery packs incorporating electronic protection circuits, such as a PCM or BMS, electrostatic discharge and protection behavior may also need to be considered according to the applicable requirements and product design.
This is particularly relevant to battery packs used in electronic products, where protection circuitry must operate reliably under electrical interference.
However, ESD requirements should not be assumed to apply identically to every IEC 61960 test configuration. The applicable requirements depend on whether the product is a cell or battery and on the specific standard edition and test configuration.
4.7 Designation, Dimensions, and Marking
IEC 61960 also includes requirements related to:
- Cell and battery designation
- Dimensions
- Marking
- Product identification
- Other information needed for consistent identification
Standardized designation and marking make it easier for purchasers and users to identify and compare battery products from different manufacturers.
5. IEC 61960-4 for Coin Secondary Lithium Batteries
IEC 61960-4 is specifically designed for coin secondary lithium cells and batteries.
The current edition, IEC 61960-4:2024, covers performance tests, designation, marking, dimensions, and other requirements for coin secondary lithium cells and batteries used in portable applications, watches, and backup power applications.
Because coin cells are much smaller than conventional cylindrical or prismatic cells, their test conditions and performance requirements need to be evaluated according to their specific characteristics.
Typical applications include:
- Wearable devices
- Watches
- Memory backup
- Medical and electronic devices
- Other compact electronic products
6. How Is IEC 61960 Testing Performed?
A typical IEC 61960 performance evaluation involves several stages.
Step 1: Confirm the Test Requirements
First determine:
- Applicable standard part
- Cell or battery type
- Required test items
- Number of samples
- Test conditions
- Required test report format
For cylindrical and prismatic lithium cells, IEC 61960-3 is generally the relevant part. For coin secondary lithium cells, IEC 61960-4 applies.
Step 2: Prepare Samples
The required number of samples depends on the test program and laboratory requirements.
The laboratory normally needs the product specification, including:
- Rated capacity
- Nominal voltage
- Charge voltage
- Discharge cutoff voltage
- Recommended charge current
- Recommended discharge current
- Cell or battery dimensions
Step 3: Perform the Tests
The laboratory conducts the specified performance tests under controlled conditions.
Depending on the test program, the process may include capacity testing, temperature performance, charge retention, cycle life, internal resistance, and other applicable evaluations.
Step 4: Issue the Test Report
The final report records the test conditions and measured results.
For supplier qualification and product development, the report can provide objective performance data for comparison between battery models or suppliers.
7. Five Practical Applications of IEC 61960 Testing
1. Cell Selection and Supplier Comparison
IEC 61960-based test data can help buyers compare cells from different suppliers based on:
- Actual capacity
- Cycle performance
- Internal resistance
- Temperature performance
- Charge retention
This is particularly useful when comparing the manufacturer’s declared specifications with independently measured results.
2. Supporting Product Datasheets
IEC 61960 test results can provide technical support for product specifications and datasheets.
Reliable test data can improve the credibility of a battery product and give customers greater confidence in the stated performance.
3. Product Performance Verification
During new product development, testing can verify whether the selected battery meets the intended performance targets.
For example, engineers can evaluate whether the battery provides the required capacity, discharge performance, and operating lifetime under the intended conditions.
4. Quality Control and Incoming Inspection
Selected IEC 61960 performance tests can also be incorporated into quality-control programs.
Capacity, internal resistance, and other performance parameters can be used to monitor batch consistency and identify abnormal cells.
5. Working Alongside Safety Certification
Performance testing and safety testing serve different purposes.
For a lithium battery product, IEC 61960 performance evaluation can be arranged alongside applicable safety testing, such as IEC 62133-2, depending on the target market and product requirements.
This allows manufacturers to evaluate both performance and safety during product development.
8. Frequently Asked Questions
Q1: Can an IEC 61960 test report be used as a market-access certificate?
Generally, no.
IEC 61960 is primarily a performance standard. A performance test report does not automatically replace safety certification or other regulatory requirements.
Depending on the product and target market, additional requirements may include IEC 62133-2, CB certification, CE-related requirements, KC, UL standards, transportation testing such as UN 38.3, or other applicable regulations.
Q2: What is the relationship between IEC 61960-3 and GB/T 18287?
GB/T 18287 is a Chinese national standard for portable lithium-ion batteries and battery packs.
There are similarities between the two standards in areas such as capacity and cycle-performance evaluation, but they are not identical standards and their detailed test conditions and scope can differ.
Therefore, the applicable standard should be selected according to the customer’s market, product, and contractual requirements.
Q3: Are IEC 61960 Parts 1 and 2 still relevant?
The historical IEC 61960 series also included standards for nickel-based secondary cells and batteries.
For lithium batteries, the relevant standards are now primarily IEC 61960-3 for prismatic and cylindrical lithium secondary cells and batteries and IEC 61960-4 for coin secondary lithium cells and batteries. IEC 61960-3:2017 replaced the 2011 edition for its covered applications.
Q4: How long does a 500-cycle test take?
The actual duration depends on the specified charge/discharge procedure, rest periods, and whether an accelerated procedure is used.
A simple calculation based only on charge and discharge time can significantly underestimate the total laboratory time because additional rest periods and test procedures may be required.
IEC 61960-3:2017 includes an accelerated cycle-life procedure, which can reduce the test duration under the specified conditions.
Q5: Is IEC 61960 testing mandatory for lithium batteries?
Not for every lithium battery product.
Whether IEC 61960 testing is required depends on the product, target market, customer requirements, procurement specifications, and internal quality-control procedures.
However, standardized performance testing can be valuable when customers need objective data for cell qualification, supplier comparison, and product performance verification.
Conclusion
IEC 61960 is an important reference for evaluating the performance of secondary lithium cells and batteries for portable applications.
The key point is that it is a performance standard, not a general safety certification.
For lithium battery sourcing and development, IEC 61960-based testing can help answer important questions:
- Does the actual capacity match the rated capacity?
- How does the battery perform at different temperatures?
- How well does it retain charge during storage?
- How does its capacity change during cycling?
- What is its internal resistance?
- Are the specifications supported by objective test data?
For battery suppliers and OEM/ODM projects, combining standardized performance data with applicable safety and transportation requirements provides a more complete basis for battery qualification.
LNC supports customized lithium-ion and LiFePO4 battery solutions, including cell selection, battery pack design, BMS configuration, performance evaluation, and OEM/ODM development.
