150-Second Battery Swaps: Inside the STT-HUB1101 Four-Bay Drone Hangar

What the exchange clock actually covers, and why a fast swap is not the same thing as a fast sortie cadence.

Ask anyone who has run an autonomous drone programme what limits it, and the answer is rarely the aircraft. It is the battery, and the person who has to be on site to change it. Hand-carried packs and portable chargers quietly put a technician back into a system that was supposed to run on its own.

The SKYHUB Air–Ground Coordinated System is built to remove that step from routine turnaround. Its core is the STT-HUB1101, a stand-alone four-bay battery-exchange hangar, paired with the STT 1S MAX four-rotor aircraft. As with every SKYHUB configuration, the hangar and aircraft are delivered to order and configured per project and site.

What happens in those 150 seconds

The hangar's published exchange cycle is no more than 150 seconds. The clock starts when touchdown is detected on the landing deck and stops when the controller confirms AIRCRAFT READY. That window includes:

1. Aircraft capture on the landing deck.
2. Ground propulsion inhibit, so the rotors cannot start while the aircraft is being handled.
3. Deck travel to the exchange position.
4. Removal of the used module into the reserved empty bay.
5. Installation of an eligible charged module.
6. Latch, contact and identity verification.
7. Tool retreat, inventory reconciliation and deck return to release height.

Roof preparation before touchdown, the operator's handover request, preflight checks, flight authorization and departure are deliberately outside the clock. The figure is a definition, not a marketing round number, and it assumes an eligible battery is available.

The hangar in numbers

• Cabinet body (W × D × H): 1200 × 1400 × 1000 mm
• Width with roof fully open: 1760 mm
• Roof aperture / landing deck: 1000 × 1000 mm / 500 × 500 mm
• Landing alignment allowance: ±40 mm
• Battery bays: 4 (one kept empty before each return)
• Charging: 3 independent channels, up to 800 W each
• Charge time: Up to ~25 min from 20% to 90% SOC at 25 °C
• Supply: 220–240 V AC, 50/60 Hz, 16 A circuit; max 3.2 kW input
• Enclosure: IP65 with roof closed
• Operating range: −20 to +50 °C; 5–95% RH non-condensing
• Local console: 10.1-inch industrial touchscreen
• Network: Gigabit Ethernet; optional cellular backhaul
• Internal cameras: 2 × 4 MP (landing zone, transfer zone)
• Local event history: 90 days

Safety design is spelled out too. The emergency-stop and access interlocks are designed to ISO 13849-1:2023 PL e / Category 4. The electrical design follows IEC 60204-1, and the enclosure is classified under IEC 60529.

The aircraft it serves

STT 1S MAX is the matched exchange aircraft. Its payload is built for inspection and security observation rather than photography:

• Imaging: three 48 MP visible cameras (wide 24 mm-equivalent, medium tele 70 mm, tele 168 mm with up to 112× hybrid zoom) and 4K30 video.
• Thermal: a 640 × 512 uncooled VOx radiometric thermal imager with ≤50 mK sensitivity, measuring from −40 to +150 °C (high gain) and 0 to +500 °C (low gain).
• Ranging and positioning: laser ranging to 1800 m (normal incidence, 20% reflectivity), integrated RTK, and ±0.1 m RTK hover accuracy.
• Obstacle sensing: omnidirectional binocular vision with downward 3D infrared.
• Endurance: up to 54 minutes of forward flight and 47 minutes of hover, both on a full 100%→0% window in windless test conditions.
• Environment: wind resistance of 12 m/s; IP55 with covers closed; −20 to +50 °C.
• Battery: 6S NMC lithium-ion, 6768 mAh, 22.14 V, 149.9 Wh, 640 g, rated for 400 cycles, with low-temperature self-heating.

The manual is careful about what these numbers mean. Maximum flight time is not a guaranteed route duration, and the 25 km (FCC) or 12 km (CE/SRRC/MIC) radio link distance is a one-way radio limit, not an approved operating radius.

Why exchange time is not sortie cadence

Swapping a battery in 150 seconds does not mean the aircraft can fly back-to-back forever. The standard delivery holds four matched modules: one in the aircraft, three in the hangar, and one bay kept empty to receive the returning pack. Every module has a unique identity and exactly one recorded location: aircraft, transfer tool or bay.

Sustainable cadence therefore depends on three things:

• How fast depleted packs recover on the three charging channels.
• How long each mission lasts.
• How many modules currently pass eligibility checks.

An occupied bay is not the same as a ready battery. A module becomes flight-eligible only at ≥90% SOC and ≥80% SOH, with resting cell spread ≤30 mV, a locked latch and no active fault. If no module is eligible, the planner offers a later departure instead of pretending one exists.

Planning a site

Because the hangar is a ground installation on AC supply, site planning matters:

• Roof travel needs 1760 mm of width.
• Maintenance access must be kept clear.
• The aircraft approach volume must be kept clear.

Open-roof recovery and exchange are suspended when precipitation, wind or other site conditions make recovery unsafe. Each site receives a configuration sheet listing the cabinet serial number, aircraft identity, the four battery IDs, software versions and authorized operators.

Talk to us about your configuration

Whether you need a single hangar for a facility or a hangar paired with SKYHUB pole nodes and ground robots, the configuration is engineered around your site, airspace permissions and operating rules. Send us your site, mission profile and timeline.