GB29743.3-2025
Motor vehicle coolant—Part 3: Fuel cell vehicle coolant
机动车冷却液 第3部分：燃料电池汽车冷却液
GB 29743.3-2025 is a current mandatory Chinese national standard for Motor vehicle coolant—Part 3: Fuel cell vehicle coolant. It appears in the Electronics compliance cluster with a product safety focus and has an implementation date of Mar 1, 2026.
Applicability depends on product scope, certification route, competent authority notices and transition rules. Requst for the translation or verify source before using this record in a compliance decision.
Compliance overview
Scope and applicability
This standard applies to the production, inspection, and use of fuel cell vehicle coolant used in the thermal management systems of fuel cell vehicle stacks. It specifically covers coolants formulated with ethylene glycol as the primary antifreeze agent. This standard is mandatory for manufacturers producing coolants for fuel cell vehicles in China. It does not apply to coolants designed for traditional internal combustion engine vehicles or electric vehicle batteries, which are covered in GB 29743.1 and GB 29743.2 respectively.
Technical requirements
The standard categorizes fuel cell vehicle coolants into concentrates (FCVC-I) and prediluted solutions (FCVC-II), with prediluted variants classified by specific freezing points. Manufacturers must ensure their products meet the strict general, physicochemical, and performance requirements outlined in the document. General requirements dictate that the coolant must be a clear, transparent liquid without precipitation or suspended matter, and possess no irritating odor. Physicochemical properties are rigorously controlled, including parameters for density, freezing point, boiling point, pH value, and ash content. A critical distinction for fuel cell applications is the strict limitation on electrical conductivity and specific harmful ions like chloride and sulfate, ensuring the coolant's insulating properties. Supplementary testing for thermal conductivity and specific heat capacity is also mandated. Performance requirements focus heavily on material compatibility and corrosion protection. The standard specifies limits for static and circulating bench corrosion tests using typical stack materials such as brass, titanium, stainless steel, graphite, and cast aluminum. Coolants must also demonstrate compatibility with rubber and plastic materials, as well as stability under thermal and low-temperature conditions. Additionally, compatibility with the vehicle's deionizer is evaluated for colored coolants.
Testing methods
- Electrical Conductivity Test: Measures the coolant's conductivity using a calibrated conductivity meter to ensure it meets the strict insulating requirements for fuel cells. - Thermodynamic Parameter Test: Utilizes the transient hot-wire method to determine thermal conductivity, thermal diffusivity, and specific heat capacity. - Static and Circulating Bench Corrosion Tests: Evaluates the mass change of typical metal and graphite test coupons after prolonged exposure to the coolant at elevated temperatures. - Material Compatibility Tests: Assesses changes in hardness, volume, and tensile strength of rubber and plastic materials after immersion in the coolant. - Stability and Deionizer Compatibility Tests: Checks for visual changes, precipitation, and conductivity shifts after thermal and low-temperature storage, as well as after circulation through a deionizer.
FAQs
What products are regulated under GB 29743.3-2025?
It regulates fuel cell vehicle coolants, specifically those using ethylene glycol as the main antifreeze, used in the thermal management systems of fuel cell stacks.
How does this standard differ from other vehicle coolant standards?
Unlike coolants for traditional engines (GB 29743.1) or EV batteries (GB 29743.2), this standard imposes strict limits on electrical conductivity and requires specific tests for deionizer compatibility and thermodynamic parameters.
Are there specific testing procedures for fuel cell coolants?
Yes, the standard includes normative appendices detailing unique test methods for electrical conductivity, thermal parameters, static/circulating corrosion, and material compatibility.
The summary above provides a high-level overview of GB 29743.3-2025. To ensure complete compliance for your products entering the Chinese market, a precise and professional translation of the full technical specifications is essential. Purchase our high-quality English translation of GB 29743.3-2025 today to access all detailed parameters, tables, and testing procedures.
Applicability hints
- Type
- Safety
- CCS
- R16
- ICS
- 03.220.20
- Competent department
- Ministry of Transport
- Technical committee
- National Technical Committee on Automobile Maintenance and Repair of Standardization Administration of China