Onboard Power Supply A4(400S50,930g) Kitefiy

Product Specification

Onboard Power Supply A4

AF-400S50-4K  |  3500W Rated / 4300W Peak  |  IP65  |  Kitefly Tethered

Product Overview

The Kitefly AF-400S50-4K is a high-power tethered UAV onboard module rated at 3500W continuous with peak capacity of 4300W at 50Vdc/80A. Now in its third generation with enhanced heat dissipation design, it is the highest IP-rated module in the standard Kitefly onboard series at IP65 — a step above IP55. Compatible with a wide range of UAV platforms including the DJI M400 series, it eliminates battery endurance constraints entirely, enabling continuous flight for as long as the mission demands.

Adopting the latest soft-switching technology with an 8:1 input/output range, the A4 achieves up to 98.3% conversion efficiency with a smooth soft-start ramp-up that protects connected drone systems during power-on. Multiple units can be paralleled for applications requiring output beyond 3500W rated power.

Key Specifications

Why Choose the A4 for Your Tethered Drone System?

The AF-400S50-4K is purpose-built for demanding tethered UAV missions — including large multi-rotor platforms, persistent surveillance operations, tethered lighting arrays, and high-power DC motor applications. Compatible with a wide range of UAV platforms operating on a 50V power architecture, including the DJI M400 series.

The IP65 rating provides full dust-tight protection and resistance to water jets from any direction — making the A4 the preferred choice for harsh outdoor environments including desert conditions in the Middle East, monsoon-affected regions in South Asia, and coastal deployments in humid climates.

Its third-generation design brings significantly improved thermal management, addressing heat dissipation demands of high-duty-cycle missions in hot climates. Multiple units support parallel operation for applications requiring beyond 3500W rated power.

Protection & Safety Features

• Output overcurrent protection: 105A (latch, recovers by power cycling)

• Output short-circuit protection (latch, recovers by power cycling)

• Over-temperature protection with auto-recovery

• Input overvoltage protection: 455–465V

• Input undervoltage protection: 310–320V

• Soft-start at power-on for smooth current ramp-up

• Insulation: Input to output 3000Vdc withstand voltage

• EMC compliant: IEC61000-4-5 Level 3 (Surge), EN55022 Class A

• Power status indicator: 2 built-in green LEDs (on during normal operation, off if fault)

Frequently Asked Questions

Q: What drone platforms is the A4 compatible with?

The A4 is compatible with a wide range of tethered UAV platforms that operate on a 50V power architecture, including the DJI M400 series. If you are unsure whether the A4 matches your specific airframe, contact us and we can advise on the right model for your setup.

Q: What does IP65 mean and why does it matter?

IP65 provides full dust-tight protection (zero dust ingress) and resistance to water jets from any direction. Compared to IP55 on other Kitefly models, IP65 offers meaningfully higher protection for extremely dusty environments such as desert operations, or in heavy rain conditions.

Q: What does 'third generation with enhanced heat dissipation' mean in practice?

The A4 has been refined over three hardware generations, with each version improving the thermal management design. The current generation is optimized for sustained high-power operation in high ambient temperature environments — critical for Middle East and South Asian deployments where ground temperatures can exceed 45°C.

Q: How long can a drone fly continuously with the A4 tethered power module?

The Kitefly tethered power system removes battery endurance as a limiting factor entirely. Unlike battery-powered drones limited to 20–40 minutes per charge, a drone connected to the A4 can fly continuously for hours or days, depending on mission requirements. Actual flight duration is governed by the drone's own motor endurance, thermal performance, and mechanical lifespan — not the power supply. For extended operations, follow your drone manufacturer's maintenance recommendations.

Q: Why does the drone need to take off with a fully charged battery?

The drone must carry a fully charged battery at all times during tethered flight. In the event of a ground power interruption, the system seamlessly switches to battery power with zero voltage transient drop, enabling a safe emergency landing. The A4 operates in parallel with the battery — not as a replacement for it.

Q: Can multiple A4 units be used together for higher power?

Yes. Multiple A4 units can be paralleled to scale total system power beyond 3500W for large-platform or multi-motor UAV configurations. Contact our team to discuss your specific power architecture requirements.

Q: What is the lead time and availability?

The A4 is available in stock for immediate shipment. If current stock is insufficient for your order, lead time is 2–3 weeks. Contact Ms. Susy for availability and volume pricing.

Related Products

A1.5 (400S24, 380g, 1500W)  |  A2 (400S48, 530g, 2000W)  |  A2.5 (400S24, 532g, 2500W)  |  A3.5 (400S48, 900g, 3200W/5000W peak)

Contact Us