1. Definition of IEC 61960

IEC 61960 is an international performance standard published by the International Electrotechnical Commission (IEC), full title: Secondary cells and batteries containing alkaline or other non-acid electrolytes — Secondary lithium cells and batteries for portable applications. It specifies unified performance evaluation rules for lithium batteries, enabling fair performance benchmarking among products from different manufacturers for purchasers and end users.

As a pure performance standard, it complements IEC 62133-2 (safety standard): IEC 62133-2 verifies whether a battery is safe, while IEC 61960 evaluates practical usability including actual runtime, cycle durability and rated capacity authenticity.

2. IEC 61960 Standard Structure

The obsolete IEC 61960:2011 (Edition 2) was formally withdrawn in April 2020 and split into two standalone valid parts for lithium cells:

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IEC 61960-3 covers most mainstream portable lithium products such as 18650, 21700, 26650 cylindrical cells and various prismatic pouch cells. IEC 61960-4 targets coin cells widely used in wearables and portable medical devices.

3. IEC 61960 vs IEC 62133-2: Performance vs Safety

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In short: IEC 62133-2 sets the minimum safety threshold to “legally sell”; IEC 61960 proves reliable performance to “sell well”. The two standards jointly build dual safety & performance compliance for lithium batteries.

4. Core Test Items of IEC 61960-3:2017 for Prismatic & Cylindrical Cells

4.1 Rated Capacity Discharge (20°C)

After standard charging (0.2C or manufacturer-specified rate), discharge at 0.2C to cut-off voltage under 20±5°C. Measured capacity shall not fall below rated nominal capacity within permitted tolerance; core test to prevent capacity overrating.

4.2 Discharge Performance at Variable Temperatures

Discharge at −20°C & 0°C with 0.2C current. Typical requirements: ≥70% nominal capacity at 0°C; 50%~60% nominal capacity at −20°C, directly determining cold-region endurance.

4.3 Charge Retention & Recovery

Fully charged cells stored for 28 days at 20±5°C (accelerated: 7 days at 40°C). General pass rules: ≥70% charge retention; ≥85% recovered capacity after full recharge, simulating warehouse & shelf-life self-discharge loss.

4.4 500-Cycle Endurance Test

Controlled charge-discharge cycling for 500 cycles at 20±5°C; accelerated cycling method available in 2017 revision. Pass: residual capacity ≥60% of nominal after 500 cycles, benchmark for long-term service lifespan.

4.5 AC Internal Resistance

1kHz alternating current method for IR measurement; results must comply with manufacturer’s declared specification. Lower IR brings steadier discharge platform and less thermal generation.

4.6 ESD Immunity Test

For packs with PCM protection circuit: ±8kV contact discharge & ±15kV air discharge to verify no malfunction or permanent damage under electrostatic interference.

4.7 Nomenclature, Dimension & Marking Rules

Standard cell naming rules (e.g. INR18650-25R coding definition), dimensional tolerance and permanent label requirements to guarantee cross-brand interchangeability and traceability.

5. IEC 61960-4:2020 Special Rules for Coin Cells

Core test categories align with Part3 (capacity, low-temp discharge, retention, cycle life, IR), while test parameters including discharge current, temperature limit and cycle cut-off are customized for tiny low-capacity coin cells commonly used in wearables and precision instruments.

6. Standard IEC 61960 Testing Process

Tests are implemented by ISO/IEC 17025 accredited third-party labs:

1. Requirement Confirmation: Confirm applicable Part (3/4), full/partial test scope, sample quantity & delivery timeline.
2. Sample Submission: 10~20 pieces per test item with complete datasheet listing nominal voltage, rated capacity and charge/discharge cut-off parameters.
3. Lab Execution: Total lead time ranges 2~8 weeks; long-cycle testing usually takes 4~6 weeks.
4. Final Report: CNAS & ILAC mutually recognized test report with side-by-side comparison of measured vs standard-limit data.

Qualified in-house labs may also issue self-declaration of conformity (DoC) without third-party testing.

7. Five Key Application Scenarios & Tips

1. Cell Vendor Comparison: Benchmark capacity, cycle life, low-temperature property and internal resistance across different cell manufacturers to avoid exaggerated nominal parameters.
2. Authoritative Datasheet Support: Attach IEC61960 test data on product specs to improve credibility for global customers.
3. New Product R&D Validation: Verify actual battery performance matches designed rated runtime and charging speed in prototype phase.
4. Incoming & Finished-Goods QC: Embed capacity & cycle tests into regular batch inspection to control production consistency.
5. Parallel Testing with Safety Certification: Run IEC61960 performance and IEC62133-2 safety tests concurrently (same or split samples) to shorten overall certification cycle.

8. FAQ

Q1: Can IEC61960 report serve as market access document? A: No. It is only for performance benchmarking; market entry relies on safety certifications such as IEC62133-2 CB, CE, KC or UL.

Q2: Relation between IEC61960-3 and GB/T 18287? A: China GB/T18287 is developed referencing core IEC61960 clauses with minor test-condition differences; GB/T preferred for domestic China business while IEC61960 for international orders.

Q3: Are IEC61960-1 & -2 still valid? A: Part1 (Ni-Cd) & Part2 (Ni-MH) remain active for nickel-based cells; Part3 & Part4 are exclusive for lithium-ion.

Q4: How long for standard 500-cycle testing? A: ~5,000 hours (~7 calendar months) under standard 0.2C cycling; accelerated protocols cut duration down to several weeks with clear annotation on final report.

Q5: Is IEC61960 mandatory by regulation? A: Non-mandatory per law; it is specified voluntarily by overseas brand buyers, procurement contracts or internal factory quality standards.

Disclaimer: All content is for reference only and not legally binding certification advice. Implementation shall follow latest official IEC published specifications.