Product Overview
The Princeton Tec Apex LED Headlamp is designed for extreme conditions, offering powerful illumination and robust durability. It features a Maxbright LED for bright, efficient light, a rechargeable battery with a power meter, and multiple beam patterns for versatility.

Image: Princeton Tec Apex LED Headlamp, showing the main light unit and the rear-mounted battery pack.
Key Features:
- Maxbright LED: Highest quality LED for extremely bright and efficient white light.
- Rechargeable Battery Power Meter: Provides continuous feedback on battery life. The rechargeable lithium-ion battery pack can be clipped to the headstrap or moved to a belt/pack with an extended power cable.
- Multiple Beams: Combines focused narrow and wide beams for versatility, offering close-range daylight simulation and distance illumination.
- Burn Time: Up to 13 hours of runtime depending on beam and mode usage.
- Waterproof (IPX7): Provides waterproof integrity down to 1 meter for up to 30 minutes.
Setup
Battery Installation and Charging
- Locate the battery compartment on the rear of the headlamp unit.
- Open the battery compartment cover. Ensure proper polarity when inserting the rechargeable lithium-ion battery pack.
- Close the battery compartment securely to maintain waterproof sealing.
- To charge, connect the provided charging cable to the battery pack and a suitable USB power source. The power meter will indicate charging status.
Adjusting the Headstrap
The headlamp features an adjustable elastic headstrap for a comfortable and secure fit. Use the buckles to tighten or loosen the strap around your head. The battery pack can be positioned on the back of your head or detached and moved to a belt or pack using the extended power cable for weight distribution.
Operating Instructions
Powering On/Off and Mode Selection
The Apex headlamp features tactile buttons for easy operation, even with gloves. The main button controls power and cycles through light modes.
- To Turn On: Press the main power button once.
- To Cycle Modes: Press the main power button repeatedly to switch between different brightness levels and beam patterns (spot, flood, or combined). The headlamp offers various settings including Spot High, Spot Med, Spot Low, Flood High, Flood Med, and Flood Low.
- To Turn Off: Hold the main power button down for approximately 2 seconds.
Battery Level Indicator
The integrated power meter provides continuous feedback on the remaining battery life, allowing you to monitor usage and plan for recharging.

Image: Performance specifications for the Princeton Tec Apex Headlamp, detailing lumen output, runtime, and beam patterns for various modes.
Maintenance
- Cleaning: Wipe the headlamp with a damp cloth to remove dirt and debris. Do not use harsh chemicals or abrasive cleaners.
- Battery Care: For optimal battery life, store the headlamp with a partially charged battery if not in use for extended periods. Recharge regularly.
- Waterproof Seal: Periodically inspect the O-rings and seals around the battery compartment and lens for any signs of wear or damage. Replace if necessary to maintain waterproof integrity.
Troubleshooting
Light Not Turning On:
- Check battery charge level. Recharge if low.
- Ensure batteries are inserted with correct polarity.
- Verify battery compartment is securely closed.
Reduced Brightness or Short Runtime:
- Battery may be low or nearing end of life. Recharge or consider replacing the battery pack if it no longer holds a charge.
- Ensure lens is clean and free of obstructions.
Specifications
| Feature | Detail |
|---|---|
| Maxbright LED | Highest quality LED available |
| White Brightness | 650 Lumens |
| Power Source | Battery Powered (Rechargeable Lithium-Ion) |
| Runtime | 13 hours (depending on mode) |
| Water Resistance Level | IPX7 (Waterproof to 1 meter for 30 minutes) |
| Item Weight | 279 Grams |
| Product Dimensions | 3"D x 6"W x 6"H |
| Model Name | APX21-BK/DK |
| Brand | Princeton Tec |
Warranty and Support
The Princeton Tec Apex LED Headlamp comes with a Lifetime Warranty.
For warranty claims, technical support, or further assistance, please visit the official Princeton Tec website or contact their customer service department. Keep your purchase receipt as proof of purchase.





