Introduction
Thank you for choosing the Kryptonite Alley F-650 Headlight. This manual provides essential information for the proper setup, operation, and maintenance of your new bicycle headlight. Please read this manual thoroughly before use to ensure safe and optimal performance.
Safety Information
- Always ensure the light is securely mounted before riding.
- Do not look directly into the light beam to avoid temporary vision impairment.
- Charge the battery fully before first use and regularly thereafter.
- Operate the light within its specified temperature range.
- Keep the light away from children.
Package Contents
Verify that all items are present in your package:
- Kryptonite Alley F-650 Headlight
- Handlebar Mounting Bracket
- USB Charging Cable
- User Manual (this document)
Setup
1. Mounting the Headlight
The Alley F-650 Headlight features a tool-free mounting bracket for easy installation and removal.
- Identify a suitable location on your bicycle's handlebar.
- Open the clamp of the mounting bracket.
- Position the bracket on the handlebar and securely close the clamp. Ensure it is tight enough to prevent movement during riding.
- Slide the Alley F-650 Headlight onto the bracket until it clicks into place.

Image: The Kryptonite Alley F-650 Headlight securely attached to a bicycle handlebar, demonstrating its compact design and front-facing illumination.
2. Charging the Battery
The Alley F-650 is equipped with a rechargeable battery. Charge the light fully before its first use.
- Locate the USB charging port on the light.
- Connect the provided USB charging cable to the light and to a standard USB power source (e.g., computer USB port, USB wall adapter).
- The built-in battery indicator will show charging status. A green light indicates a full charge, while a red light indicates the battery is below 25%.
- Charging time may vary depending on the power source. Disconnect the cable once fully charged.
Operating Instructions
Power On/Off
- To turn the light ON, press and hold the power button for approximately 1 second.
- To turn the light OFF, press and hold the power button for approximately 1 second.
Changing Lighting Modes
Once the light is on, short press the power button to cycle through the 6 available lighting modes:
- High Steady: Maximum brightness for clear visibility. (Run time: 2 hours)
- Medium Steady: Balanced brightness for general use. (Run time: 4 hours)
- Low Steady: Extended run time for less demanding conditions. (Run time: 12 hours)
- Daytime Pulse: Distinct flash pattern for enhanced daytime visibility. (Run time: 8 hours)
- Nighttime Pulse: Unique flash pattern for increased visibility at night. (Run time: 10 hours)
- Economic Flash: Longest run time, suitable for emergencies or extended rides. (Run time: 26 hours)
Special Features
- Memory Function: The light will turn on in the last mode it was set to before being turned off.
- Eco Mode: When the battery level drops to 10% or less, the light will automatically switch to the lowest lumen output (Economic Flash) to conserve power and help you reach your destination safely.
- Side Illumination Ports: Designed to provide enhanced visibility from the sides, increasing safety when crossing traffic lanes.
Maintenance
Cleaning
Wipe the light's exterior with a soft, damp cloth. Do not use abrasive cleaners or solvents, as these can damage the casing or lens.
Battery Care
- For optimal battery life, avoid completely draining the battery frequently.
- Charge the light at least once every three months, even if not in use, to maintain battery health.
- Do not attempt to replace the internal battery. Contact Kryptonite support for service.
Storage
Store the light in a cool, dry place away from direct sunlight when not in use for extended periods.
Troubleshooting
- Light not turning on: Ensure the battery is charged. Press and hold the power button for 1 second to activate.
- Light not charging: Check the USB cable connection and the power source. Try a different USB cable or power adapter.
- Short run time: Ensure the battery is fully charged. Run time varies significantly by mode; higher brightness modes consume more power. Battery performance may decrease over time with extensive use.
Specifications
| Model | Alley F-650 |
| Lumen Output | 650 Lumens |
| Power Source | Rechargeable Battery (USB) |
| Lighting Modes | 6 (High Steady, Medium Steady, Low Steady, Daytime Pulse, Nighttime Pulse, Economic Flash) |
| Run Times | High Steady: 2 hrs, Medium Steady: 4 hrs, Low Steady: 12 hrs, Daytime Pulse: 8 hrs, Nighttime Pulse: 10 hrs, Economic Flash: 26 hrs |
| Water Resistance | Water Resistant |
| Material | Plastic |
| Weight | 0.4 Pounds (approx. 181 grams) |
| Dimensions (L x W x H) | 1.45" x 4.25" x 2.9" (approx. 3.68cm x 10.8cm x 7.37cm) |
| Mounting Type | Handlebar Mount (Tool-Free) |
Warranty and Support
Specific warranty information is not provided in this manual. For warranty details, technical support, or service inquiries, please refer to the official Kryptonite website or contact Kryptonite customer service directly. Keep your proof of purchase for warranty claims.