1. Introduction
Thank you for choosing the Alonefire SV52 25W UV LED 365nm Rechargeable Flashlight. This professional-grade ultraviolet flashlight is designed for a wide range of applications, offering a powerful 365nm UV light source with a high-quality black filter lens for pure and effective UV output. Please read this manual thoroughly before use to ensure safe and optimal performance.

The Alonefire SV52 UV Flashlight, showing its powerful UV beam, included USB-C charging cable, and protective glasses.
2. Safety Information
WARNING: Ultraviolet (UV) light can be harmful to eyes and skin. Always follow these safety guidelines:
- Eye Protection: Always wear the provided UV protective glasses when operating the flashlight. Never look directly into the UV light source.
- Skin Exposure: Avoid prolonged direct exposure of skin to UV light.
- Children: Keep the flashlight out of reach of children.
- Heat: The flashlight may generate heat during extended use. Handle with care.
- Battery Safety: Use only the specified rechargeable battery. Do not attempt to disassemble or short-circuit the battery.
- Disposal: Dispose of batteries and electronic components according to local regulations.
3. Package Contents
Verify that all items are present in your package:
- Alonefire SV52 UV LED Flashlight
- Rechargeable Lithium-ion Battery (pre-installed or separate)
- USB Type-C Charging Cable
- UV Protective Glasses

The complete package contents of the Alonefire SV52 UV Flashlight.
4. Product Overview
The Alonefire SV52 features a robust design and specialized components for optimal UV performance.
Key Features:
- High-Quality 365nm UV LED: Utilizes a professional 365nm UV LED as the light source, providing 25W power consumption and 4800mW light output for effective detection.
- Black UV Filter Lens: Equipped with a hardened optical black filter lens that filters out ambient visible light, ensuring a purer and more powerful ultraviolet beam.
- Durable Aluminum Alloy Shell: Constructed from high-quality aluminum alloy, enhancing heat dissipation and ensuring reliability and durability.
- USB Type-C Rechargeable: Supports convenient USB Type-C charging.
Component Identification:

Detailed view of the flashlight components.

Illustration of the black UV filter lens function.

Comparison of 365nm vs. 395nm UV light effectiveness.
5. Setup
5.1 Battery Installation
The Alonefire SV52 comes with a rechargeable Lithium-ion battery. Ensure the battery is correctly inserted with the positive (+) terminal facing towards the lamp head.
5.2 Initial Charging
Before first use, fully charge the flashlight. Connect the provided USB Type-C cable to the flashlight's charging port and to a compatible USB power source (e.g., computer, power adapter, power bank, car charger).
- The charging indicator light will be red during charging.
- The charging indicator light will turn green when fully charged.

Charging the Alonefire SV52 via USB Type-C.
6. Operation
6.1 Powering On/Off
To turn the flashlight ON, press and hold the power switch for approximately 3 seconds. To turn it OFF, press and hold the power switch again for 3 seconds.

Proper grip and power switch location.
6.2 Usage Guidelines
Always wear the provided UV protective glasses before activating the flashlight. Direct the UV beam towards the area you wish to inspect. The 365nm wavelength, combined with the black filter lens, ensures that fluorescent materials glow brightly while minimizing visible light interference.
7. Applications
The Alonefire SV52 UV flashlight is suitable for various professional and household applications:
- Pet Urine and Stain Detection: Identify hidden pet stains on carpets, rugs, and upholstery.
- Mineral and Gemstone Inspection: Observe fluorescence in various minerals, amber, and gemstones.
- Currency and Document Verification: Check security features on banknotes, passports, and other official documents.
- Scorpion Detection: Scorpions fluoresce brightly under 365nm UV light, making them easy to spot in dark environments.
- Resin Curing: Accelerate the curing process of UV-sensitive resins.
- Fishing Lure Charging: Charge fluorescent fishing lures for enhanced visibility.
- Hygiene Inspection: Detect invisible contaminants in bathrooms, kitchens, and other areas.



8. Maintenance
8.1 Cleaning
Wipe the flashlight body with a soft, damp cloth. Do not use abrasive cleaners or solvents. Keep the lens clean for optimal light output.
8.2 Storage
Store the flashlight in a cool, dry place away from direct sunlight and extreme temperatures. If storing for an extended period, remove the battery or ensure it is charged periodically to maintain battery health.
9. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Flashlight does not turn on. | Battery is depleted. Battery is incorrectly installed. Power switch malfunction. | Charge the battery. Check battery polarity. Contact customer support if issue persists. |
| Light output is weak. | Battery is low. Lens is dirty. | Recharge the battery. Clean the lens with a soft cloth. |
| Flashlight gets hot during use. | Normal operation for high-power UV LED. Prolonged use. | This is normal. Discontinue use if it becomes excessively hot. Ensure proper ventilation. |
| Charging indicator does not light up. | Charging cable is not properly connected. USB power source is faulty. | Ensure cable is securely connected. Try a different USB power source. |
10. Specifications
| Feature | Detail |
|---|---|
| Brand | ALONEFIRE |
| Model Number | SV52 |
| Light Source Type | 365nm UV LED |
| Power Consumption | 25W |
| UV Light Output | 4800mW |
| Material | Aluminum Alloy |
| Color | Black |
| Power Source | Battery Powered (Rechargeable) |
| Battery Type | 1 Lithium-ion (Included) |
| Charging Port | USB Type-C |
| Item Weight | 380 grams |
| Package Dimensions | 18.4 x 8.8 x 5.7 cm |
| Special Features | High Power, Rechargeable, Black Filter Lens |
11. Warranty and Support
For warranty information or technical support, please refer to the documentation provided with your purchase or contact the retailer/manufacturer directly. Keep your purchase receipt as proof of purchase.

