New China EV Battery Standard Enhances Performance Testing Framework
A landmark update in China’s electric vehicle (EV) battery testing landscape has been introduced with the release of GB/T 31467—2023, a comprehensive standard that redefines how lithium-ion battery packs and systems are evaluated for electrical performance. This new national standard, titled Electrical Performance Test Methods for Lithium-Ion Traction Battery Packs and Systems in Electric Vehicles, consolidates and modernizes previous testing protocols, aligning them more closely with real-world driving conditions, evolving technological capabilities, and international benchmarks.
The revision marks a significant shift from the earlier dual-structure standards—GB/T 31467.1—2015 for high-power applications and GB/T 31467.2—2015 for high-energy applications—into a single, unified framework. This consolidation not only streamlines testing procedures but also reflects the growing convergence of power and energy requirements in modern EV platforms, where vehicles must deliver both high performance and extended range under diverse operating conditions.
Developed by the China Automotive Technology and Research Center Co., Ltd. (CATARC), one of the country’s leading automotive R&D and standardization institutions, the updated standard addresses critical gaps identified in the 2015 versions. As the Chinese EV market has matured, so too have consumer expectations and engineering demands. Battery performance is no longer assessed solely on capacity or peak power, but on a broader spectrum of metrics including charging behavior, thermal resilience, energy efficiency, and real-world usability.
One of the most notable advancements in GB/T 31467—2023 is the introduction of three new test items: energy density, charging performance, and operational discharge (commonly referred to as “driving cycle” ). These additions respond directly to market-driven needs. Energy density, a key determinant of vehicle range and packaging efficiency, now has a standardized measurement methodology within the official testing framework. Previously, this metric was evaluated using interim guidelines not formally codified in national performance standards, leading to inconsistencies across manufacturers and testing bodies.
The inclusion of charging performance testing is particularly timely. With rapid charging infrastructure expanding across China and global markets, consumers increasingly prioritize how quickly their vehicles can recharge. The new standard specifies charging tests under four distinct temperature conditions—room temperature, 40 °C, 0 °C, and Tmin (a minimum temperature agreed upon between manufacturer and customer). This multi-temperature approach ensures that battery systems are evaluated not only under ideal conditions but also in extreme environments where charging efficiency and safety are most challenged.
Charging strategies are now required to reflect real-world battery management systems, incorporating dynamic adjustments based on state of charge (SOC) and internal temperature. Test results must include detailed data curves capturing voltage, current, temperature, and SOC over time, enabling deeper analysis of charging behavior and thermal management effectiveness.
Similarly, the addition of operational discharge testing allows for a more realistic assessment of battery performance. Instead of relying solely on constant-current discharge profiles, the standard recommends using driving cycles derived from the China Light-duty Vehicle Test Cycle (CLTC), which better represents typical urban and highway driving patterns in Chinese cities. This method captures transient power demands, regenerative braking effects, and variable load conditions that are absent in traditional lab tests. By simulating actual road usage, engineers can gain more accurate insights into how a battery system will perform over time, improving both design validation and consumer confidence.
Beyond these new test categories, GB/T 31467—2023 incorporates numerous refinements to existing procedures. A major focus has been on harmonizing test conditions across different performance metrics. For instance, the standard now mandates consistent temperature settings for tests such as no-load capacity loss, energy efficiency, and cold/high-temperature cranking power. The high-temperature storage condition for no-load capacity loss has been raised from 40 °C to 45 °C, reflecting the increasing frequency of extreme heat events and the need to evaluate battery durability under more severe thermal stress.
The standard also introduces clearer definitions for thermal equilibrium during environmental adaptation. Instead of relying solely on fixed dwell times, it now requires that the battery pack or system reaches a state where cell temperatures vary by no more than 2 °C from the target ambient temperature within a one-hour window without active cooling. This ensures that thermal gradients within the pack are minimized before testing begins, leading to more repeatable and reliable results.
Data collection protocols have been tightened as well. To support advanced analytics and model validation, the maximum interval between data recordings has been reduced to 100 seconds, replacing the previous requirement of recording at least every 1% of charge or discharge duration. This enables finer resolution in tracking dynamic responses during pulse tests, efficiency measurements, and transient events.
In the realm of power and internal resistance testing, the updated standard enhances precision by specifying a maximum data sampling interval of 100 milliseconds during pulse events. This allows for accurate capture of voltage transients and immediate response characteristics, which are crucial for assessing a battery’s ability to support acceleration, regenerative braking, and grid stabilization functions in hybrid or plug-in hybrid vehicles.
To prevent potential damage during high-power testing, the standard includes a protective mechanism: if the battery voltage reaches a preset limit before the full pulse duration is completed, the test allows for current reduction to avoid overvoltage or overcurrent conditions. Additionally, charging at temperatures below the battery’s minimum allowable threshold is explicitly prohibited, safeguarding against lithium plating and irreversible degradation.
Another significant refinement is the adjustment of current rates used in standard cycling and capacity testing. For high-energy applications, the discharge rate has been changed from 1 C to 1/3 C, better reflecting the typical discharge profiles seen in long-range EVs rather than high-performance sports models. This change acknowledges that most modern EVs operate in a moderate power range most of the time, and testing should mirror this reality.
The standard also revises SOC adjustment procedures to improve test efficiency. Previously, adjusting the battery to a target SOC often required a full charge-discharge cycle, even if the battery was already near the desired state. Under the new rules, if the last SOC adjustment occurred within 24 hours, the process can begin from any starting point, eliminating unnecessary cycling and reducing test time and wear on the sample.
Energy efficiency testing has been updated to reflect current technological capabilities. In earlier standards, fixed high-current rates (e.g., 20 C discharge, 15 C charge) were mandated regardless of whether the battery could actually support them. The new version removes these rigid requirements, instead aligning the test with the battery’s actual maximum allowable pulse currents (I’max(SOC,T,t)). This shift makes the test more representative of real-world operation and avoids forcing batteries into unrealistic operating regimes simply to meet a testing criterion.
For high-energy battery systems, the low-temperature charging test at Tmin has been simplified by removing outdated 1 C charging requirements that were incompatible with modern low-temperature charging protocols. Instead, the standard now emphasizes consistency between pre-conditioning cycles and the final efficiency calculation, ensuring that the measured energy input and output reflect the same operating conditions.
The standard also clarifies the role of thermal management systems during testing. For tests directly related to vehicle operation—such as energy efficiency, charging performance, and operational discharge—the use of active cooling or heating is recommended to simulate real-world conditions. For other tests focused on intrinsic battery characteristics, thermal management should generally be disabled unless otherwise agreed upon, to isolate the electrochemical performance of the cells themselves.
Weight and dimensional measurements have been restructured to improve clarity. The standard now explicitly defines which components are included in mass calculations—such as integrated thermal management systems—while excluding removable non-battery parts like external coolant lines. Volume measurement, previously required, has been removed due to its limited relevance in performance evaluation.
Capacity and energy testing now include additional data logging requirements, such as recording the time evolution of total pack voltage, individual cell voltages (maximum and minimum), and temperature monitoring points. These data streams are essential for diagnosing cell imbalance, thermal runaway risks, and control system effectiveness.
The revision process for GB/T 31467—2023 was informed by extensive industry consultation, real-world vehicle data, and alignment with international standards—particularly ISO 12405-4:2018, which serves as a key reference. However, the Chinese standard is not a direct adoption; it includes several enhancements tailored to domestic conditions, such as the use of CLTC-based driving cycles and specific temperature points relevant to China’s diverse climate zones.
This balance between global harmonization and local adaptation strengthens China’s position in the international EV standards community. It enables Chinese manufacturers to produce batteries that meet both domestic and export market requirements, while also contributing to the evolution of global best practices.
From a regulatory and consumer perspective, the updated standard enhances transparency and comparability. Automakers and battery suppliers now have a clearer, more rigorous framework for validating their products. Independent testing agencies can conduct evaluations with greater consistency, reducing discrepancies between labs. Consumers benefit from more reliable performance claims, knowing that advertised metrics like range, charging speed, and cold-weather performance are backed by standardized, repeatable tests.
For researchers and developers, the standard provides a robust foundation for innovation. By defining clear test methods and acceptance criteria, it reduces ambiguity in R&D programs and accelerates the development cycle. The inclusion of advanced metrics like energy efficiency and operational discharge encourages the design of smarter battery management systems and more resilient cell chemistries.
Moreover, the emphasis on real-world relevance helps bridge the gap between laboratory results and on-road performance. This is critical as the EV industry moves toward more sophisticated vehicle-to-grid (V2G) applications, second-life battery reuse, and predictive maintenance systems—all of which depend on accurate models of battery behavior under dynamic conditions.
The publication of GB/T 31467—2023 also signals a maturation of China’s EV ecosystem. Early standards were often reactive, designed to catch up with technological trends. Today’s standards are proactive, shaping the direction of innovation and setting performance expectations before new technologies reach mass production.
As the global transition to electrified transportation accelerates, the role of robust, science-based standards cannot be overstated. They ensure safety, reliability, and fair competition while fostering trust among consumers, regulators, and investors. GB/T 31467—2023 exemplifies this principle, offering a comprehensive, forward-looking framework that supports the continued growth of the EV industry.
In conclusion, the revised GB/T 31467—2023 standard represents a major step forward in the evaluation of lithium-ion battery systems for electric vehicles. By integrating new test methods, refining existing procedures, and aligning with real-world usage patterns, it provides a more accurate, reliable, and meaningful assessment of battery performance. As China continues to lead in EV adoption and battery innovation, this standard will play a crucial role in maintaining quality, driving technological advancement, and building consumer confidence in electric mobility.
Niu Pingjian, Hao Weijian, Su Zhiyang, Shi Shengkun, Liu Shaohui, China Automotive Technology and Research Center Co., Ltd., Energy Storage Science and Technology, doi: 10.19799/j.cnki.2095-4239.2024.0288