GB/T 47136-2026Specification for the assessment of the health and safety state of traction batteries for battery electric vehicles (English PDF)

1 Scope

This document specifies the assessment process, assessment index system, calculation method, assessment results, applications for the health and state-of-safety assessment of power batteries for pure electric vehicles.

This document applies to activities conducting health and state-of-safety assessments of power batteries for in-service pure electric vehicles based on operational data.

Activities conducting health and state-of-safety assessments of power batteries used in other scenarios shall refer to this document.

This document applies to ternary lithium batteries and lithium iron phosphate batteries; other types of power batteries shall refer to this document for further information.

2 Normative references

The following documents, through normative references within this document, constitute essential provisions of this document. For dated references, only the edition cited applies; for undated references, the latest edition of the referenced document (including any amendments) applies.

GB/T 19596-2017 Terminology of electric vehicles

GB/T 32895-2025 Communication protocols for swapping battery pack of electric vehicle

GB/T 32960.3-2025 Technical specifications for remote service and management system for electric vehicles - Part 3: Communication protocol and data format

GB/T 38661-2020 Technical specifications of battery management system for electric vehicles

GB/T 45415-2025 Defect analysis methods for battery electric vehicles fire accidents

3 Terms and definitions

The terms and definitions defined in GB/T 19596-2017 and GB/T 45415-2025, as well as the following terms and definitions, apply to this document.

4 Assessment process

The assessment process for the health and state-of-safety of power batteries is shown in Figure 1 and includes the following.

- Determine the assessment object and clarify the health and state-of-safety assessment indicator system. If significant deformation or cracking of the power battery casing is found during the determination of the assessment object, the health and state-of-safety assessment shall be stopped; a risk assessment and defect analysis of the power battery shall be conducted.

- State-of-health assessment. Calculate the state-of-health assessment indicator values; calculate the total state-of-health score; generate a state-of-health assessment result report.

- State-of-safety assessment. Based on the total state-of-health score, calculate the state-of-safety assessment indicator values and assess whether there are any high-risk safety conditions. If a high-risk condition exists, a state-of-safety assessment result report is generated directly; if no high-risk condition exists, the total state-of-safety score is calculated; a state-of-safety assessment result report is generated.

5 Assessment indicator system

5.1 The state-of-health assessment indicator system consists of four assessment dimensions. capacity, voltage, internal resistance, usage behavior. It includes six assessment indicators. capacity retention rate, voltage deviation mean value change, voltage range root mean square, internal resistance consistency, cumulative charge/discharge cycles/cumulative service life, average monthly charge/discharge cycles. The indicators and their weights are shown in Table 1.

5.2 The state-of-safety assessment indicator system consists of three assessment dimensions. state-of-health, electrical safety, thermal safety. It includes seven assessment indicators. annual decline rate of SOH, minimum parallel unit overvoltage, minimum parallel unit undervoltage, insulation resistance failure, poor voltage consistency, high battery temperature, battery temperature difference. See Table 2 for each assessment indicator.

5.3 The assessment indicator system for the state-of-health and state-of-safety of power batteries in pure electric vehicles can be used for the development of power battery analysis systems.

6 Calculation methods