SOFIRN SP31 V3.0 Tactical LED Flashlight User Manual

1. Setup

1.1 Package Contents

Please check the package for the following items:

• SOFIRN SP31 V3.0 Flashlight
• 18650 Battery (3000mAh)
• USB Type-C Charging Cable
• Lanyard
• 2x Spare O-rings
• User Manual (this document)

Image showing the flashlight, battery, USB-C cable, lanyard, O-rings, and user manual.

1.2 Battery Installation

1. Unscrew the tail cap of the flashlight.
2. Insert the included 18650 battery with the positive (+) terminal facing towards the flashlight head.
3. Remove the insulating paper disc from the battery if present.
4. Screw the tail cap back on tightly.

Caution: Do not unscrew the flashlight head or sealed components, as this may damage the flashlight and void the warranty.

1.3 Charging the Flashlight

The SP31 V3.0 features a USB Type-C charging port for convenient direct charging.

1. Locate the USB Type-C port on the flashlight body (usually covered by a rubber flap).
2. Open the rubber flap to expose the port.
3. Connect the included USB Type-C charging cable to the flashlight and to a USB power adapter (not included).
4. It is recommended to use a USB power adapter with a maximum output of 5V/2A.

Charging Indicator:

• Red Flashing: Charging in progress
• Green Constant Light: Fully charged

Image showing the flashlight connected to a power bank via USB-C cable, with charging indicators.

Note: Only low mode is available when the flashlight is charging.

1.4 Initial Use

After installing the battery and ensuring it's charged, the flashlight is ready for operation.

2. Operating Instructions

The SP31 V3.0 features a dual-switch design: a tactical tail switch and a side electronic switch.

2.1 Power On/Off

• To Turn On/Off: Press the tactical tail switch.

2.2 Mode Switching

When the flashlight is ON:

• Brightness Levels (Low/Medium/High/Turbo): Click the side electronic switch to cycle through these modes.
• Moonlight Mode: From ON, press and hold the side electronic switch, then click the tactical tail switch.
• Strobe Mode: From ON, press and hold the side electronic switch to enter Strobe mode.
• SOS/Beacon Mode: While in Strobe mode, click the side electronic switch to cycle through SOS and Beacon modes.
• Exit Strobe/SOS/Beacon: Press and hold the side electronic switch.

Diagram illustrating the operation logic of the SP31 V3.0 with tail and side switches.

2.3 Battery Level Indicator

After turning on the SP31 V3.0, the indicator light on the side switch will display the power status for 5 seconds:

• Solid Green: 70% - 100% battery remaining
• Solid Red: 30% - 70% battery remaining
• Flashing Red: 1% - 30% battery remaining (recharge or replace promptly)

Image showing the green, red, and flashing red battery indicators.

2.4 Advanced Temperature Regulation (ATR)

In High or Turbo mode, the flashlight may heat up. To prevent overheating, the SP31 V3.0 monitors its temperature and automatically adjusts to lower brightness levels when the internal temperature reaches 55°C.

Official product video demonstrating unboxing, battery installation, and basic operation.

3. Maintenance

3.1 Cleaning

• Clean the threads and O-rings with a soft cloth.
• Apply a thin layer of silicone grease to the threads and O-rings every 6 months to maintain proper waterproof performance.

3.2 Battery Care

• If the flashlight will not be used for an extended period, please remove the battery to prevent potential leaks or damage.
• To prevent accidental discharge or activation during storage or transport, slightly loosen the tail cap.

3.3 O-Ring Replacement

Replace worn O-rings with the approved spare ones provided in the package to ensure the IP68 waterproof rating is maintained.

4. Troubleshooting

4.1 Flashlight Not Turning On

• Check if the battery is inserted correctly with the positive (+) terminal facing the head.
• Ensure the tail cap is screwed on tightly.
• Verify the battery is charged.
• Check for any insulating paper disc that might still be present between the battery and contacts.

4.2 Dim Light or Unexpected Shutdown

• The battery might be low. Recharge or replace the battery promptly.
• If the battery voltage drops below 2.7V, the flashlight will automatically turn off.
• The ATR system might have reduced brightness due to high temperature. Allow the flashlight to cool down.

4.3 Charging Issues

• Ensure the USB-C cable is properly connected to both the flashlight and the power source.
• Try a different USB power adapter or cable.
• Check if the charging port is clean and free of debris.

4.4 Low Voltage Warning

When the flashlight is powered on, if the battery voltage is lower than 3.15V, the red indicator will flash for 5 seconds. If the battery voltage is lower than 3.0V, the red indicator will keep flashing, signaling that the battery power is poor and requires immediate recharging or replacement.

5. Specifications

5.1 Performance Table (SST40 LED - 2000lm)

Detailed product parameters table for SOFIRN SP31 V3.0.

5.2 Emitter Comparison

Comparison of SP31 V3.0 with 519A Green (1200lm, 5000K) and SST40 Black (2000lm, 6000-6500K).

6. User Tips

• The dual-switch design (tail and side) is highly convenient for quick operation and mode changes.
• The tail switch is effective in reducing accidental activation, making it suitable for tactical use or carrying in a bag.
• For general use and accurate color rendition, the 519A LED (5000K) provides a comfortable light that is pleasing to the eyes.
• The USB-C charging feature is very practical for on-the-go recharging.
• Its compact size makes it an excellent choice for everyday carry (EDC) without being bulky.

7. Warranty and Support

SOFIRN products are manufactured to high-quality standards. For any issues, questions, or warranty claims, please contact your seller or SOFIRN customer support directly. Please provide your purchase details and product model number for faster assistance.

Note: Disassembling the flashlight head or sealed components will void the warranty.