Overview
ISO/TR 11954:2024 - “Fuel cell road vehicles - Performance measurement - Vehicles fuelled with compressed hydrogen” - is a Technical Report from ISO that specifies standardized test methods to measure driving performance of fuel cell hybrid electric vehicles (FCHEV) (passenger cars and light‑duty trucks up to 3 500 kg) using compressed hydrogen. The second edition updates scope, adds driving performance tests and definitions, and revises preconditioning and RESS (rechargeable energy storage system) state‑of‑charge procedures.
Key topics and technical requirements
- Scope and vehicle type: Applies to FCHEV passenger cars and light‑duty trucks with maximum authorised total mass ≤ 3 500 kg, fuelled with compressed hydrogen.
- Performance tests specified:
- Maximum speed and maximum thirty‑minutes speed (v30)
- Acceleration ability (e.g., 0 → 50 km/h, 50 → 80 km/h)
- Speed uphill (highest average speed on a given slope over 1 km)
- Hill starting ability (maximum slope to start over 10 m)
- Preconditioning and test sequencing:
- Hydrogen refuelling procedures and fuel quality per ISO 14687 (or regional equivalent)
- RESS state‑of‑charge (SOC) adjustment and preconditioning for externally chargeable FCHEV
- Vehicle warm‑up, driving mode selection and minimum pre‑use driving distance (≥ 300 km with onboard fuel cell)
- Test conditions and constraints:
- Ambient temperature ranges: outdoor 5 °C–32 °C, indoor 20 °C–30 °C; atmospheric pressure 91–104 kPa
- Air density limited to ≤ 7.5% deviation from reference (formula provided)
- Track and tyre conditions, vehicle loading to specified test mass and standard accessory settings
- Measurement parameters and accuracies (examples):
- Time ±0.1 s; distance ±0.1 %; speed ±1 % or ±0.1 km/h; mass ±0.5 %; tyre pressure ±1.5 %
- DC current measurement considerations for pulsed power electronics and RESS energy measurement
Applications and users
ISO/TR 11954:2024 is practical for:
- Vehicle manufacturers developing and validating FCHEV performance and drivability
- Test laboratories and certification bodies conducting standardized performance trials
- Regulators and type‑approval authorities assessing compliance and safety claims
- R&D teams, fleet operators and energy infrastructure planners evaluating hydrogen vehicle capabilities
The standard provides repeatable, comparable test methods to benchmark acceleration, hill climb, sustained speed and hill‑start performance for compressed‑hydrogen FCHEV.
Related standards
Keywords: ISO/TR 11954:2024, fuel cell hybrid electric vehicle, FCHEV, compressed hydrogen, performance measurement, acceleration, maximum speed, hill climbing, RESS SOC, hydrogen fuel quality.