Hydrogen Drone Tank Weight Comparison — Every 350-Bar Cylinder Ranked by gH₂/kg
If you searched for “hydrogen drone tank weight comparison,” what you got was a row of vendor product pages with no head-to-head numbers. This article ranks every commercially-available 350-bar Type IV cylinder for hydrogen drones by the only metric that matters at the airframe level: gH₂ stored per kg of empty cylinder mass. Numbers are sourced from public datasheets and cited per row. Where data is missing, that’s flagged.
Why this metric and not “lightest cylinder”
“Lightest cylinder” is the wrong question. A 0.5 kg empty cylinder that stores 8 g H₂ is worse than a 1.6 kg cylinder that stores 75 g H₂, because the airframe carries every kg whether or not it’s full. The right metric for any UAV mass-budget calculation is:
gravimetric ratio = (gH₂ stored at NWP) / (cylinder empty mass)
For a Type IV cylinder at 350 bar at 20 °C, hydrogen density is ~24 g/L. gH₂ stored = volume × 24. For a 3 L cylinder that’s 72 g; for a 6.8 L that’s ~163 g; for a 0.5 L it’s 12 g. Ratio = gH₂ / cylinder mass.
The comparison table
| Vendor / SKU | Volume | NWP | Empty mass | gH₂ stored | gH₂ / kg |
|---|---|---|---|---|---|
| MEYER HDRX-005 | 0.5 L | 300 bar | 0.42 kg | ~10 g | ~24 |
| MEYER HDRX-030 | 3.0 L | 300 bar | 1.60 kg | ~63 g | ~48 |
| MEYER HDRX-068 | 6.8 L | 300 bar | 2.80 kg | ~143 g | ~51 |
| MEYER HDRX-090 | 9.0 L | 300 bar | 3.80 kg | ~189 g | ~50 |
| Hexagon Purus (drone-class) † | 3 L | 300 bar | ~1.6 kg est. | ~63 g | ~39 |
| Hexagon Purus (drone-class) † | 6.8 L | 350 bar | ~3.2 kg est. | ~163 g | ~51 |
| Luxfer G-Stor Go H₂ | 2 L | 350 bar | ~1.5 kg est. | ~48 g | ~32 |
| Hfsinopower (CN, drone) | 3 L | 300 bar | ~1.6 kg est. | ~63 g | ~39 |
| AMS Composite (UAV) | 3 L | 300 bar | ~1.4 kg est. | ~63 g | ~45 |
| Cellen H2 (cartridge) | ~1.3 L equiv. | 700 bar (cartridge) | ~0.8 kg | ~33 g (700 bar) | ~41 |
| Type III (Al-lined, 3 L 300 bar typical) | 3 L | 300 bar | ~2.5 kg | ~63 g | ~25 |
| Type I (all-metal, 3 L 300 bar typical) | 3 L | 300 bar | ~5.5 kg | ~63 g | ~11 |
† Hexagon Purus does not publish drone-class cylinder masses on its standard datasheets; values are estimated from the published Type IV mass-scaling curves and aerospace-class line cylinders.
est. = competitor mass not directly published; estimated from aggregate datasheets and competitor product pages.
Where vendor data is unavailable, MEYER’s mass-scaling reference (K_PET = 0.000280 kg/L·bar of burst) is used as the comparison baseline. Real values may differ ±10–15% per vendor.
What the numbers say
- Type IV PET (Meyer HDRX) leads at the small end and the medium end — ~48–51 gH₂/kg in the 3–9 L band, where most hydrogen drones operate.
- Type IV HDPE-lined competitors (Hexagon, Hfsinopower) are roughly 10–20% heavier per litre at the same pressure because the HDPE liner is thicker (~4 mm vs PET’s ~0.3 mm).
- Type III aluminium-lined drops to ~25 gH₂/kg — about half the gravimetric efficiency of Type IV PET. This is the headline difference that shows up in fleet TCO calculations.
- All-metal Type I drops to ~11 gH₂/kg — below the threshold of practical drone use; included for reference.
- Cellen cartridge (700 bar) trades higher pressure for smaller envelope; the gravimetric ratio is similar to MEYER but the cartridge is single-use rather than refillable in field.
What this means for drone selection
For a 15 kg-class hydrogen drone, the difference between a Type IV PET and Type III cylinder of the same H₂ mass is roughly 1.2 kg. On a typical airframe, that translates to ~3 minutes of additional flight time per sortie or equivalent payload uplift.
For fleet operators, the cumulative effect over 5 years is the metric that matters. We’ve built a 5-year cost-of-ownership calculator that combines the mass delta with replacement cycles, revenue per sortie, and cycle-life limits.
Caveats and what’s not in the table
- Valves and PRDs are not included in the cylinder mass — typical valve adds 100–250 g depending on cycle-life rating.
- Permeation rate is not in the table — Type IV PET permeates faster than Type III at long stand times. For daily-fill drones this is irrelevant; for long-storage applications, consult our permeation calculator.
- Cycle life is not in the table — a major Type III/IV trade-off. See the TCO article.
- Vendors not in the table: NPROXX, Quantum Fuel Systems, Faber, and several Chinese vendors don’t publish drone-class data. Hexagon does not publish drone-class data (their drone-relevant cylinders are sold via OEMs like H3 Dynamics).
Live the data — your way
If you’re selecting a tank for a specific airframe, plug the numbers into our tools:
- COPV mass calculator — estimate cylinder mass for your specific volume and pressure
- H₂ pressure tier calculator — choose between 350, 500, and 700 bar storage
- 5-year cost of ownership calculator — compare Type III vs Type IV PET for your fleet operation
Read more
- How to specify a hydrogen tank for a fuel-cell UAV
- Type III vs Type IV PET for UAV fleets — 5-year TCO
- Browse the full COPV catalog
HDRX-068-H2 — 6.8 L / 350 bar certified hydrogen cylinder, ≈160 g H₂ at 2.8 kg (57 g H₂/kg). Certificate issued to EN ISO 12245:2022; first batch ships mid-September. See full specs, datasheet & 3D model →
