China Proposes Strict New Standards for Underground Mine Lithium Batteries - G/TBT/N/CHN/2257

by Fares

Overview

China has issued a new draft national standard, GB XXXXX—XXXX, outlining the technical conditions for lithium-ion traction batteries used in underground mines. Proposed by the National Mine Safety Supervision Bureau, this regulation is critical for international exporters and trade professionals, as it introduces new safety and performance benchmarks for a specialized product category within a high-risk operational environment.

Key Details

Country / Notifying Member: China
Document Symbol: G/TBT/N/CHN/2257
Notification Date: 2026-06-01
Proposed date of adoption: To be determined
Proposed date of entry into force: 12 months after approval
Comment Deadline: 31 July 2026
Objective: To establish comprehensive technical requirements, inspection rules, transportation, and storage requirements for lithium-ion traction batteries applied in underground mines, thereby enhancing safety and performance standards for critical equipment.

What Is Being Regulated

This proposed standard specifically covers "lithium-ion traction batteries applied in underground mines" (地下矿山用锂离子动力电池), defined as lithium-ion accumulators providing power for underground mining equipment, where battery cells have a nominal capacity greater than 10 Ah. The regulation applies to the design, manufacture, and inspection of these batteries. It references GB 38031—2025 "Electric vehicles power battery safety requirements" as a normative document. The relevant ICS codes are 29.220.10 and 73.100.99, and the CCS code is K 82.

Key Requirements & Technical Changes

The standard introduces extensive requirements for both individual battery cells and complete battery modules:

Normal Working Conditions: Batteries must operate normally between -30℃ and 60℃, and at altitudes up to 5000 m.
Basic Requirements: Batteries must have a unique, traceable code for product specifications, model, and manufacturer information, clear positive/negative markings, clean appearance free from mechanical damage, and conform to the manufacturer's specified structure, dimensions, and mass.
Battery Cell Technical Requirements (5.3):
- Electrical Performance: Actual capacity must be 93%–110% of rated capacity, with a maximum 3% range for the average. Cycle life requires retaining at least 93% of actual capacity over 500 cycles.
- Safety Performance: Cells must undergo rigorous tests including over-discharge, over-charge, high-temperature and low-temperature charge/discharge cycling, external short circuit, drop, heating, squeezing, and shallow puncture. Expected outcomes generally prohibit thermal runaway, fire, explosion, leakage, or shell rupture (except for pressure relief structures).
- Specific Tests: Includes thermal runaway tests (trigger methods aligned with GB 38031-2025), pressure relief structure tests (opening pressure within manufacturer specs, no leakage before opening), and diaphragm heat resistance tests (longitudinal and transverse thermal shrinkage less than 5%).
Battery Module Technical Requirements (5.4):
- Electrical Performance: Actual capacity must be 93%–110% of rated capacity, with a maximum 3% range for the average. Battery consistency requires a voltage range coefficient not greater than 5.
- Safety Performance: Modules are subject to similar safety tests as cells, including over-discharge, over-charge, high/low-temperature charge/discharge cycling, external short circuit, drop, heating, and squeezing, with outcomes prohibiting fire, explosion, leakage, or shell rupture (except for pressure relief structures).
Test Methods (Section 6): Specifies detailed environmental conditions, measurement accuracy for instruments (e.g., voltage/current ±0.5%FS, temperature ±0.5℃), and process control error margins. Outlines procedures for standard charging, pre-treatment cycles (3 for cells, 2 for modules), and basic visual, dimensional, and mass checks, as well as specific test methodologies for each electrical and safety performance requirement.
Inspection Rules (Section 7): Defines inspection classifications, items, sampling procedures, and judgment rules.
Transportation and Storage (Section 8): Outlines requirements for safe transportation and storage.

Link to the notification: G/TBT/N/CHN/2257

Link to the Draft standard: Technical conditions of lithium-ion traction batteries for underground mines