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Reviews > Lighting > Headlamps - LED > Princeton Tec Fuel headlamp > Owner Review by Bob Dorenfeld

Princeton Tec - Fuel
Owner Review By Bob Dorenfeld
May 13, 2014

Tester Bio
Name: Bob Dorenfeld

I'm an active hiker, snowshoer, skier, and backpacker.  Home base is the Southern Colorado Rockies, where I'll hike from 7000 ft (2100 m) to above treeline, with desert trips to lower altitudes.  Six to 12 miles (10 to 20 km) daily is my norm, with elevation gains up to 4000 ft (1200 m).  Many of my backpack trips are two or three nights, other trips are longer, and I usually carry about 30 lbs (14 kg).  My style is lightweight but not obsessively so - extras like binoculars, camera, and notebook make my trips more enjoyable.

Email: geartest(at)sageandspruce(dot)net
Age: 56
Location: Salida, Colorado, USA
Gender: M
Height: 5' 6" (1.68 m)
Weight: 140 lb (64 kg)

Product Overview

Manufacturer:    Princeton Tec
MSRP:    Unavailable
Illumination:  70 lumens
Lamp:  4 LEDs
Burn Time:  146 hours
Batteries:  3 AAA
Listed Weight (w/ batteries):  2.75 oz (78 g)
Verified Weight: (w/ batteries): 2.75 oz (78 g) 
Available Colors:  Black/Charcoal, Green/Charcoal, Pink/Charcoal

 Princeton Tec Fuel
Photo:  Princeton Tec
The Princeton Tec Fuel is a lightweight headlamp using an LED lamp array powered by three AAA batteries.  It is water resistant (but not immersible), the headband is made of stretchy material, and its length is adjustable using the built-in strap buckle.  The top-located power switch cycles through each of four lighting modes on successive clicks: high, medium, low, and flash.  All LEDs light up on each cycle.  The headlamp beam angle can be aimed up or down by rotating the entire body on its axis.  The Fuel comes in three color combinations, and includes three AAA batteries in the package.

Field Performance    

The Princeton Tec Fuel headlamp has been in production since at least 2008 when I purchased my first one.  I have several of these in the black and green color combinations.  Since there is a large selection of LED headlamps on the market, narrowing the field of options can be difficult; but I like the Fuel's ease of operation and its overall dependability (with one exception regarding the battery door, described below). I estimate that I've used this headlamp model on about 40 backpack and other camping trips.  I like having an extra for loaning to a friend who lacks a headlamp for our trips.  Some of my Fuels have three-lamp LED array, while the latest model has a four-lamp array; Princeton Tec has changed the design sometime since I started using them.

Preparing and using the Fuel is not complicated.  Adjusting the headband length is easy using the slider buckle on the strap.  Depending on whether or not I'm wearing a hat, it takes me only a few seconds to get the headband comfortable around my forehead, and its length seems generous enough for the largest head plus a hat.  The batteries are loaded from the side of the case after snapping open the thin plastic lock tab.  But be careful here: applying too much pressure all at once, or from the corners instead of the center, may eventually break the tab.  If it breaks only at one side, as I have done several times on different headlamps, the lid will still close (see photo).  However, if both sides break then the lamp will be rendered useless (unless tape or another method is used to keep the battery door closed). broken tab Although a coin or the back of a knife blade can be used to gently pry the lid, Princeton Tec has molded a correctly-sized and shaped blunt edge into the headband buckle, and that probably works best.  On their website Princeton Tec calls this their "virtually bulletproof, easy access battery door", but I think that there is room for improvement in the design. 

I always note the battery polarity indicators before sliding in the batteries - two are negative-side up, one positive-side up.  Batteries can be either non-rechargeable or rechargeable; I've used both over the years, with no practical differences in performance for me.  (Note: discharge times may differ between the battery types, as well as voltage, but I haven't measured them with this headlamp.)

Once I'm wearing the headlamp, turning it on is via a firm press of the single button on the top of the case.  I like that it takes some pressure - this keeps the lamp from operating unintentionally when stored in my pack or anywhere else where it's not needed.  The first press of the button puts the Fuel in high power/brightness.  Second press is medium brightness, third is low, and the fourth press blinks at approximately once per second at high brightness.  If more than about a second passes between button presses, then the next press will turn the lamp off.  A final option is to press and hold the power button (when the light is off) - the lamp will stay on at the highest brightness until the button is released.  Changing the vertical direction of the light is simple: just rotate the case up or down as it "bumps" over internal ridges.  Like the power button, rotating the case takes firm pressure, but that also keeps it from moving when it's not supposed to.  The maximum downward angle of the light (measured from horizontal) is 70° and the maximum upward angle is 45° (see photo).Max downward angle

In practice, I've never had a use for pointing the lamp up, and directing the light straight out or down is where I almost always keep it set, either slightly down for moving about camp, or all the way down for reading.  Also, in practice, I almost never use the two brightest settings - I find that the extra light is unnecessary, and I can get longer life from the batteries by using the lowest power mode exclusively.  I've also never had to use the flashing mode, but in an emergency or for signaling across a distance it could be useful.

Although I find that wearing any headlamp for a long period of time is not very comfortable, the Fuel's light weight, thin layer of padding on the headband, and slight curve molded into the case is sufficient to keep it comfortable enough for the time I need it at night around camp - usually about an hour or so, sometimes longer. 

Over the years I've found the Fuel to be quite water resistant for normal use around camp.  Although I've never had to test this water resistance for hours at a time in a driving rainstorm, it's never failed on me due to water infiltration when exposed for short periods to either rain or snow. 

I've noticed over the years that the clear plastic lens does get lightly scratched, but I don't see any effect on the light quality.  I do try to pack my headlamps with the headband wrapped around the lens to reduce the chance of scratching.

Concerning battery life, I have not verified Princeton Tec's claim of "146 hours of light" from a single set of new AAA batteries.  However, since I average no more than, say, 4-6 hours of headlamp usage on a 3-4 night backpack trip, I can easily make one set of batteries last over 2-3 months (including inactive time between backpack trips, when the batteries continue to drain power slightly).  In my experience the light maintains good to excellent brightness for most of the installed batteries' life, fading only toward the end.  That's good for preserving good light, but bad for knowing when the batteries need to be replaced.  I always carry a spare set!  In between camping trips, storing alkaline batteries in the refrigerator can extend their life.  Finally, I try to never store batteries in the headlamp for more than a couple of weeks at a time, since they can possibly leak and ruin the interior of the headlamp.

Concluding Thoughts    

To sum up, the Princeton Tec Fuel headlamp is one of the most reliable pieces of electronic gear in my pack.  I also keep one in my daypack for emergencies.  The Fuel is comfortable, easy to use, comes in pleasant colors (well, the black and green anyway), and has a long burn time.

  • lightweight
  • bright illumination
  • easy push-button operation
  • easy tilt adjustment to angle light up or down
  • water resistant

  • battery-door lock tab prone to breaking if not opened carefully

 Reviewed By
Bob Dorenfeld
Southern Colorado Mountains

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Reviews > Lighting > Headlamps - LED > Princeton Tec Fuel headlamp > Owner Review by Bob Dorenfeld

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