IEC 62660-1 - Battery Design

IEC 62660-1 is an international standard published by the International Electrotechnical Commission (IEC) that specifies performance and life testing of secondary lithium-ion cells used for the propulsion of electric road vehicles. It establishes standardised test procedures and conditions for characterising cells in battery electric vehicle (BEV) and hybrid electric vehicle (HEV) applications, providing a common basis for comparing cell performance across manufacturers and designs.

Published by: International Electrotechnical Commission (IEC), Technical Committee 21 — Secondary Cells and Batteries
Current edition: IEC 62660-1:2018 (Edition 2.0, December 2018)
Replaces: IEC 62660-1:2010 (Edition 1)

Scope

IEC 62660-1 covers secondary lithium-ion cells used for propulsion in BEV and HEV applications. The standard defines test procedures to obtain essential performance characteristics including capacity, power density, energy density, storage life, and cycle life. It applies at the cell level; it does not apply to battery packs, modules, or assembled battery systems.

Secondary lithium-ion cells used in plug-in hybrid electric vehicles (PHEV) may be tested under either the BEV or HEV procedure, depending on battery system design, as agreed between the cell manufacturer and the customer.

Safety requirements for lithium-ion cells for EV propulsion are covered separately in IEC 62660-3. Reliability and abuse testing is covered in IEC 62660-2.

Key Test Methods

The standard specifies the following test procedures:

Capacity test — Measures discharge capacity at standard conditions (23 ± 2 °C) and optionally at low temperature (−10 °C or −20 °C). Separately specified for BEV and HEV applications.
Power test — Pulse discharge at multiple states of charge (SoC) to determine available power as a function of SoC. Revised in Edition 2 for clarification.
Energy efficiency test — Measures round-trip energy efficiency over a standard charge/discharge cycle.
Storage life test — Capacity retention measured after storage at elevated temperature (e.g. 45 °C) for a defined period, evaluating calendar aging.
Cycle life test — Repeated charge/discharge cycling to determine capacity fade over cycle count. BEV procedure uses full depth of discharge; HEV procedure uses a partial charge window representative of hybrid usage.
Current–voltage characteristic test — Informative characterisation of cell internal resistance via current interruption or pulse; moved to Annex C in Edition 2.

Test conditions (temperature, charge/discharge rates, cut-off voltages) are specified for both BEV and HEV application classes. All tests are performed on cells in the as-received condition unless otherwise agreed.

Regional Adoption

IEC 62660-1:2018 has been adopted in Europe as EN IEC 62660-1 and in the UK as BS EN IEC 62660-1. It is widely referenced in automotive OEM cell specifications and procurement standards globally. No mandatory regulatory requirement in a specific jurisdiction mandates IEC 62660-1 directly, but compliance is common in supply chain agreements for EV cell qualification.

Related Standards

IEC 62660-2 — Reliability and abuse testing for EV Li-ion cells
IEC 62660-3 — Safety requirements for secondary lithium-ion cells for propulsion of electric road vehicles
IEC 62619 — Safety requirements for secondary lithium-ion cells and batteries for industrial applications
UN 38.3 — Transport testing of lithium cells and batteries
EU Battery Regulation — Regulatory framework for batteries placed on the EU market

Disclaimer: this is not a definitive guide, just an indication and it is important that you always go back to the source for legislation.