1. Introduction
The XDFly HPRO 125A Electronic Speed Controller (ESC) is a high-performance device designed for 500-550 class RC helicopters and fixed-wing aircraft. It features a powerful 32-bit G4 microprocessor, a built-in SBEC, advanced telemetry capabilities, and multiple protection functions to ensure reliable and efficient operation of your model. This manual provides essential information for the proper installation, operation, programming, and maintenance of your HPRO 125A ESC.

2. Key Features
- High-Performance Processor: Equipped with a 32-bit G4 microprocessor operating at up to 170MHz for efficient control.
- Advanced Power MOSFET: Utilizes a new generation of power MOSFETs for low heat generation, high instantaneous current endurance, and enhanced reliability.
- Comprehensive Self-Check: Automatically performs self-checks upon power-on for power supply short circuit, motor phase loss, throttle zeroing, and voltage range.
- Optimized Heat Dissipation: Features a special and unique full metal CNC case design with a temperature-controlled fan that activates above 40°C for rapid and efficient heat dissipation.
- Built-in SBEC: Integrated Switch BEC with adjustable output from 6-12V and a continuous current of 10A (peak 35A).
- Helicopter Speed Governor: Includes a governor function with adjustable sensitivity for stable rotor speed.
- Stall Landing Function: Manually adjustable time selection for stall landing to prevent crashes from handling errors.
- Flexible Programming: Supports parameter adjustment via Phone APP (Android/iOS) and various remote control devices (Mikado VBCT/E, Rotorflight2, Jeti).
- Real-time Telemetry: Provides telemetry data for Mikado VBCT/E, Rotorflight2, Futaba SBUS2, Jeti, MSH Brain, and iKon systems, allowing real-time monitoring of RPM, battery voltage, current, capacity consumption, MOSFET temperature, ESC status, and throttle values.
- RGB Status Lights: Features colorful RGB LED lights with five optional colors (red, green, blue, yellow, white) to indicate ESC status through various flashing modes.
- Multiple Protections: Includes safeguards against abnormal power-on voltage, start-up issues, over-temperature, throttle signal loss, over-load, low-voltage, and over-current.
- Autorotation Bailout: Quickly increases head speed to prevent crashes during autorotation.
- Synchronous Rectification: Reduces heat and improves efficiency.
- OTA Update: Supports firmware upgrades via Phone APP with a BLE module.



3. Specifications
| Feature | Detail |
|---|---|
| Model | HPro 125A SBEC |
| Continuous Current | 125A |
| Peak Current | 200A |
| Input Voltage | 3-8S Lipo Battery |
| BEC Output | 6-12V adjustable, 10A continuous, 35A peak |
| Dimensions (L x W x H) | 90 x 43 x 25 mm |
| Weight | 178g |
| Programming Method | XDFly Android & iOS APP, Mikado VBCT/E, Rotorflight2, Jeti remote control devices |
| Telemetry Support | Mikado VBCT/E, Rotorflight2, Futaba SBUS2, Jeti, MSH Brain, iKon |
| Applications | 500-550 class electric helicopters, fixed-wing aircraft |
| Material | Composite Material, Full Metal CNC Case |
| Recommended Age | 14+ years |

4. Setup: Installation and Wiring
Proper installation and wiring are crucial for the safe and optimal performance of your ESC. Always ensure your model's power system components (motor, battery, receiver) are compatible with the HPRO 125A ESC specifications.
4.1 Physical Installation
- Mount the ESC in a location that allows for adequate airflow to utilize its heat dissipation features effectively.
- Ensure the ESC is securely fastened to prevent movement during flight, using double-sided tape or zip ties.
- Avoid mounting the ESC directly next to sensitive electronic components that could be affected by electromagnetic interference.
4.2 Wiring Connections
Refer to the diagram below for typical wiring connections. Always double-check polarity before connecting the battery.
- Battery Connection: Connect the main power leads (red and black) from the ESC to your LiPo battery. Ensure correct polarity (red to positive, black to negative).
- Motor Connection: Connect the three motor phase wires from the ESC to your brushless motor. The order of connection may affect motor rotation direction; this can be adjusted later if needed.
- Receiver/Flight Controller Connection: Connect the signal cable from the ESC to the throttle channel of your receiver or flight controller. The built-in SBEC provides power to the receiver/flight controller.

4.3 BEC Output
The integrated SBEC provides a stable power supply for your receiver and servos. The output voltage is adjustable between 6-12V. Ensure the selected voltage is compatible with your receiver and servos.
5. Operating Instructions
5.1 Power-On Sequence and Self-Check
After connecting all components, ensure your transmitter's throttle stick is at the lowest position. Connect the battery to the ESC. The ESC will perform a self-check, indicated by a series of beeps and LED flashes. If any issues are detected (e.g., power supply short circuit, motor phase loss, incorrect throttle zeroing, or out-of-range voltage), the ESC will signal an error. Correct any detected issues before proceeding.
5.2 Throttle Calibration
For optimal performance, calibrate the ESC's throttle range with your transmitter. Consult your transmitter's manual for specific throttle calibration procedures. Generally, this involves powering on the ESC with the throttle at maximum, then moving it to minimum when prompted.
5.3 Helicopter Speed Governor Function
The HPRO 125A ESC includes a governor function to maintain a constant rotor speed. This function's sensitivity can be adjusted via the programming interface to suit your flying style and model requirements. Refer to the programming section for details on adjusting governor settings.
5.4 Stall Landing Function
This feature allows for a manually adjustable time selection during stall landing, which can help prevent crashes due to handling errors. Configure this setting through the programming interface as per your preference.
5.5 RGB Light Indications
The colorful RGB LED lights indicate the current status of the ESC. The lights can display five optional colors (red, green, blue, yellow, white) and use various flashing modes to communicate operational status or error conditions. Refer to the programming section to customize light colors.
6. Programming
The HPRO 125A ESC offers flexible programming options to customize its parameters. It features an independent programming interface.
- Smartphone App: Use the XDFly Android or iOS APP to adjust parameters. This method typically requires a Bluetooth Low Energy (BLE) module for connection.
- Remote Control Devices: The ESC supports parameter adjustment via specific remote control devices such as Mikado VBCT/E, Rotorflight2, and Jeti transmitters. Consult the respective device manuals for detailed programming instructions.
6.1 Firmware Updates (OTA)
The ESC supports Over-The-Air (OTA) firmware updates. This allows you to update the ESC's firmware using the Phone APP in conjunction with a BLE module, ensuring you always have the latest features and improvements.
7. Telemetry
The HPRO 125A ESC provides real-time telemetry data, allowing you to monitor critical flight parameters. It supports multiple protocols and can be integrated with various telemetry systems.
- Supported Systems: Mikado VBCT/E, Rotorflight2, Futaba SBUS2, Jeti, MSH Brain, and iKon.
- Available Telemetry Data:
- RPM (Revolutions Per Minute)
- Battery Voltage
- Current Consumption
- Capacity Consumption
- MOSFET Temperature
- ESC Status
- Input Throttle
- Output Throttle

8. Maintenance
To ensure the longevity and reliable performance of your HPRO 125A ESC, follow these maintenance guidelines:
- Keep Clean: Regularly inspect and clean the ESC to remove dust, dirt, and debris, especially from the cooling fins and fan area.
- Heat Dissipation: Ensure the ESC's mounting location allows for proper airflow. The smart temperature-controlled fan will automatically activate when the temperature exceeds 40°C to maintain optimal operating temperatures.
- Connection Integrity: Periodically check all wiring connections for looseness, corrosion, or damage. Secure any loose connections and replace damaged wires immediately.
- Visual Inspection: Look for any signs of physical damage, such as cracked casing, burnt components, or swollen capacitors. If damage is found, discontinue use and contact support.
9. Troubleshooting
The HPRO 125A ESC is equipped with multiple protection features to safeguard itself and your model. Understanding these protections can help in troubleshooting common issues.
- Abnormal Power-On Voltage: If the input voltage is outside the 3-8S LiPo range, the ESC will not arm. Check your battery voltage and connections.
- Start-Up Issues: If the motor does not start or stutters, check motor phase wire connections, ensure throttle is calibrated, and verify the motor is not obstructed.
- Over-Temperature Protection: If the ESC's internal temperature exceeds safe limits, it will reduce power or shut down. Allow the ESC to cool down, check for adequate airflow, and ensure the fan is operating correctly.
- Throttle Signal Loss: If the ESC loses the throttle signal from the receiver, it will enter a failsafe mode (typically motor off). Check receiver and transmitter connections, battery levels, and signal range.
- Over-Load Protection: If the motor draws excessive current, the ESC will protect itself. This can be caused by an oversized propeller, a binding drivetrain, or an incorrectly geared setup.
- Low-Voltage Protection: When the battery voltage drops below a safe threshold, the ESC will reduce power or cut off the motor to protect the battery from over-discharge. Land immediately if this occurs.
- Over-Current Protection: Similar to over-load, this protects against sudden spikes in current. Check for short circuits in the motor or wiring.
If you encounter persistent issues not covered here, consult the XDFly support resources or contact customer service.
10. User Tips
While no specific user reviews or Q&A were provided, here are some general tips for maximizing the performance and lifespan of your ESC:
- Initial Setup: Always perform a thorough throttle calibration and motor direction check before the first flight.
- Parameter Tuning: Experiment with governor sensitivity and stall landing settings in a safe environment to find what works best for your model and flying style.
- Telemetry Monitoring: Utilize the telemetry features to monitor key parameters like battery voltage and MOSFET temperature during initial flights to ensure your setup is operating within safe limits.
- Wiring Management: Keep all wiring neat and secure to prevent accidental disconnections or interference.
- Environmental Considerations: Avoid operating the ESC in excessively dusty, wet, or hot conditions beyond its design limits.
11. Warranty and Support
For warranty information, technical support, or service inquiries, please contact your retailer or the manufacturer directly. Keep your proof of purchase for any warranty claims.



