ISO 12405-4:2018

Overview

Standard Reference: ISO 12405-4:2018
Title: Electrically propelled road vehicles - Test specification for lithium‑ion traction battery packs and systems - Part 4: Performance testing

ISO 12405-4:2018 defines standardized performance test procedures for lithium‑ion traction battery packs and systems used in electrically propelled road vehicles. It covers test methods to evaluate energy, capacity, power, internal resistance, state-of-charge (SOC) losses, cranking power, energy efficiency (including fast‑charging), and cycle life for both high‑power (e.g., HEVs, some FCVs) and high‑energy applications (e.g., BEVs, PHEVs, some FCVs).

Key topics and technical requirements

The standard organizes tests and requirements to ensure repeatable, comparable performance measurements:

• General requirements: test sequencing, measurement accuracy, preparation of packs/systems for bench testing.
• Preconditioning and Standard Cycle (SC): procedures to bring the battery to defined test states.
• Energy & capacity tests: at room temperature and across multiple temperatures and discharge rates to determine rated capacity.
• Power characterization: pulse power profiles and internal resistance assessment for peak and continuous power capability.
• SOC loss & storage tests: no‑load SOC loss and SOC loss during storage to quantify self‑discharge behavior.
• Cranking power: low‑ and high‑temperature cranking tests relevant for start/stop and auxiliary loads.
• Energy efficiency: round‑trip efficiency measurements including tests specific to fast charging.
• Cycle life: accelerated cycling procedures and pass/fail criteria to evaluate longevity and degradation behavior.
• Informative annexes: test overviews, example data sheets and test condition examples.

The standard does not specify cell‑level tests (see IEC 62660 series); it focuses on pack/system level performance and electrical functionality.

Practical applications

ISO 12405-4 is used to:

• Benchmark and compare battery pack performance across suppliers.
• Validate design targets for energy, power, thermal management and charge strategies.
• Establish test protocols for R&D, validation labs and component verification.
• Support procurement specifications and supplier acceptance testing.
• Provide reproducible inputs for vehicle integration, warranty assessment and end‑of‑life planning.

Who should use this standard

• EV and vehicle OEMs specifying traction battery requirements.
• Battery system and pack manufacturers developing and validating products.
• Independent test laboratories and certification bodies performing performance verification.
• R&D teams assessing new cell chemistries, BMS algorithms and thermal designs.
• Regulators and fleet operators requiring standardized performance metrics.

Related standards

• IEC 62660 series - cell‑level test specifications for lithium‑ion traction cells.
• ISO 6469‑1 - general safety requirements for electrically propelled vehicles.
• ISO 12405 (other parts) - related test specifications for traction batteries.
• ISO 19453‑6 - forthcoming environmental test guidance referenced for broader testing contexts.

Keywords: ISO 12405-4:2018, battery pack testing, EV battery performance, lithium‑ion traction battery, cycle life, energy efficiency, SOC loss, internal resistance.