Overview
QC/T 743 is a Chinese automotive industry standard specifying requirements and test methods for lithium-ion batteries used in electric vehicles. Originally issued in 2006 by the Ministry of Industry and Information Technology (MIIT), the standard was the first dedicated Chinese regulatory framework for EV lithium-ion batteries and established the foundational approach to cell and module level testing for the Chinese EV market.
QC/T 743 has since been largely superseded by the national standards GB/T 31485 (cell and module safety) and GB/T 31486 (cell and module performance), which were developed from the QC/T 743 framework but with updated requirements, extended scope, and alignment with the accelerated growth of the Chinese EV industry from 2015 onwards. Despite this, QC/T 743 remains historically significant and is still referenced in some procurement and compliance contexts.
Scope
QC/T 743 applies to single lithium-ion cells with a nominal voltage of 3.6 V and modules comprising multiple such cells (nominal voltage n × 3.6 V, where n is the number of cells in series) intended for use in electric vehicles. The standard covers requirements, test methods, inspection rules, marking, packaging, transportation, and storage conditions for lithium-ion batteries at the cell and module level.
Key Requirements
The standard specifies requirements for electrical performance, including capacity, energy density, and charge/discharge characteristics, as well as safety requirements covering behaviour under abuse conditions. Products must meet defined thresholds for capacity retention, internal resistance, and self-discharge rate. Under safety testing, cells and modules must not exhibit fire or explosion under any of the defined abuse test conditions.
Testing Requirements
QC/T 743 specifies both performance tests and safety tests. Performance tests include capacity measurement at standard and low temperatures, charge retention and recovery after storage, internal resistance measurement, and cycle life testing. Safety tests include overcharge, over-discharge, external short circuit, mechanical crush, drop, thermal abuse (oven heating), and vibration testing. Vibration resistance was categorised as a safety test in QC/T 743, distinguishing it from later national standards such as GB/T 31486, which reclassified vibration as a performance test reflecting a different interpretation of the failure mode.
Pass/fail criteria for safety tests require that cells and modules do not catch fire or explode. Some tests also restrict electrolyte leakage. Performance test pass/fail thresholds are defined numerically for each measured parameter.
Relevance to Battery Design
Although largely superseded by GB/T 31485 and GB/T 31486 for new product development, QC/T 743 remains relevant as a historical reference point for understanding the evolution of China’s EV battery regulatory framework. Engineers working on legacy product lines or reviewing historical compliance documentation may encounter QC/T 743 certification data. For new products targeting the Chinese market, compliance with the current national standards (GB/T 31485 for safety and GB/T 31486 for performance) is the appropriate path, but QC/T 743 test data can provide useful supplementary evidence of cell robustness under conditions directly comparable to the modern standard requirements.
References
- QC/T 743-2006 Lithium-ion batteries for electric vehicles, Ministry of Industry and Information Technology (MIIT), China