IEC 61960-4:2024

Overview - IEC 61960-4:2024 (Coin secondary lithium cells)

IEC 61960-4:2024 specifies performance tests, designations, markings, dimensions and other requirements for coin secondary lithium cells and batteries used in portable applications - including watches and memory/backup power. The standard defines minimum performance levels and a standardized methodology for testing, measurement and reporting so purchasers, designers and manufacturers can assess and compare coin lithium batteries reliably. Watch‑specific requirements are contained in Annex A, and design guidance for equipment makers is in Annex B.

Key topics and technical requirements

• Scope and chemistry: Covers coin rechargeable lithium cells and batteries with a range of electrochemical couples and their characteristic nominal and end‑of‑discharge voltages.
• Designation and marking: Standardized cell naming, marking requirements and identification rules for safe use and traceability.
• Dimensions and size codes: Defined dimensional drawings and size codes (including watch battery dimensions in Annex A).
• Electrical tests:
  • Charging procedure for test purposes and recommended upper charge voltages.
  • Discharge performance and recommended end‑of‑discharge voltages.
  • Capacity recovery after long‑term storage.
  • Endurance (cycle life) testing with minimum cycle numbers.
  • Cell/battery internal (AC) resistance measurement and acceptance criteria.
• Watch‑specific tests (Annex A): Physical requirements, leakage‑resistance testing (high temperature/humidity and temperature cycling), visual examination and acceptance criteria for secondary watch batteries.
• Guidance for designers (Annex B): Practical recommendations for integrating coin lithium batteries into equipment (mechanical, electrical and safety considerations).
• Normative references: Links to related safety and terminology standards used for correct application.

Practical applications and users

Who benefits from IEC 61960-4:2024:

• Battery manufacturers - to design, test and declare compliant coin lithium cells and batteries.
• Product designers and OEMs (watches, wearable devices, memory backup modules, small portable electronics) - to select suitable coin rechargeable batteries and follow integration guidelines.
• Purchasers and test labs - to evaluate vendor claims using standardized test methods and reporting.
• Certification bodies and quality managers - to verify minimum performance, markings and test results.

Related standards

• IEC 62133-2 (safety requirements for portable lithium systems)
• IEC 60086-4 (safety of lithium primary batteries)
• IEC 60050-482 (terms & definitions for cells and batteries)

Keywords: IEC 61960-4:2024, coin secondary lithium cells, coin lithium batteries, watch batteries, performance tests, battery dimensions, internal resistance, cycle life, portable applications.