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Reviews > Lighting > Headlamps - LED > Princeton Tec Byte Headlamp > Test Report by Andrew Henrichs

Princeton Tec Byte Headlamp

Test Series by Andy Henrichs

March 29, 2011

Initial Report - 10-30-10

Field Report - 1-14-11

Long Term Report - 3-29-11


Biographical Information

Name:  Andy Henrichs
Age: 30
Gender:  Male
Height:  6 ft 2 in (1.88 m)
Weight:  185 lb (83.9 kg)
Email address:  andyhenrichs(at)gmail(dot)com
City, State, Country:  Carbondale, Colorado, USA

Backpacking Background

   Most of my backpacking has been in the mountains of Colorado and the deserts in the southwestern US.  I have gone winter camping several times but I still prefer backpacking in the warmer months.  Most of my trips are 2-3 days, but I have taken several trips of 5-6 days.  In the summer of 2004, I was fortunate enough to have thru-hiked the 476 mile Colorado Trail over 35 days.  Recently, I have been leaning towards the lightweight side of the spectrum. 


Initial Report


Product Information

Manufacturer:  Princeton Tec (

Year of Manufacture: 2010
MSRP: $19.99 US
Manufacturers Stated Weight: 2.25 oz (64 g)
Measured Weight (including batteries): 2.23 oz (63.1 g)


the Byte

The Princeton Tec Byte.

Product Description

The Princeton Tec Byte Headlamp is a lightweight headlamp designed for camping, climbing, or running. It features a single Maxbright LED and a single Ultralight Red LED. The Maxbright LED emits a standard white light and features a high and low setting. The Byte runs on two AAA batteries (alkaline or lithium), which are included. The Byte is initially packaged in three "pieces." These are the batteries, the headlamp body, and the adjustable elastic headband. The headband is black with small red squares and features the Princeton Tec logo in white, as well as the letters "PTEC," also in white. The headband adjusts from approximately 13 in (33 cm) to 24 in (61 cm) in circumference. The headband attaches to the headlamp body quite easily by slotting the band thorough small openings on each end of the headlamp body.

The body itself is black and is approximately 2.25 in (5.7 cm) by 1.5 in (3.8 cm) at the widest points. There is a slightly curved section (where the headband attaches) connected to one end of the body at a pivot point. This pivot point allows approximately 45 degrees of upward rotation and approximately 80 degrees of downward rotation. The other end of the body contains the battery compartment door. This light gray door secures with a simple "tab in the hole" mechanism. It is incredibly easy to open and seems to secure quite well. The top of the headlamp body is home to a light gray power button. The first push turns on the Ultralight Red LED, the second turns on the low setting of the Maxbright LED, the third turns on the high setting of the Maxbright LED, and the fourth turns the headlamp off.

According to the packaging, the batteries will last for 80 hours on the high Maxbright LED setting, 96 hours on the low Maxbright LED setting, and 146 hours on the Ultralight Red LED setting. The packaging also states that fresh batteries will illuminate 30 m (98 ft) on the high Maxbright LED setting, 15 m (49 ft) on the low Maxbright LED setting, and 6 m (20 ft) on the Ultralight Red LED setting.

The pivot point The battery compartment (open)

The gray plastic to the right of the LEDs is the pivot point.

The open battery compartment illustrating the tab (on the body) and the hole (on the cover door) that secures it.

LED view

The Maxbright LED is on the left and the Ultralight Red LED is on the right.

Initial Impressions

While simple, the Princeton Tec Byte appears to be a nice compact LED headlamp. It's very easy to adjust the headband to fit my head, and it appears there is enough adjustment available to fit over a climbing helmet. I will verify this during the testing session. I have never used a headlamp with a red light on it before, so I'm anxious to determine if it really does spare my night vision. When using it around the house (without having first established my night vision), the red light allowed me to make out objects just out of arms reach. Both of the Maxbright LED settings provided much more illumination, as one would expect. The pivot point of the Byte seems to be substantial, but I will reserve final judgment until I have completed my test. One thing I did notice is that the body cannot rotate far enough to cover the power button. I will be interested to see if the Byte ever becomes accidentally switched on in my pack, although the force necessary to actually depress the button to turn it on makes me think this won't be an issue. The battery cover door closes very securely, but I will be anxious to see if repeated openings and closings eat away at the plastic of the closing mechanism, rendering it less secure.

Field Report

Field Conditions

I have used the Princeton Tec Byte on eight different days over the past two months. My first use was while car camping near Moab, Utah. The elevation was approximately 4,400 ft (1,300 m) and temperatures dipped to approximately 45 F (7 C) during the night. Beautifully clear skies allowed me to camp out sans tent or other shelter. The headlamp was used only during the first evening, and it served typical camp use after dark: reading, finding objects, and illuminating my path to and from my sleeping bag. My next three uses took place at a local ski resort. I skinned up the resort around dusk and skied down in the dark. The elevation at the top of the resort was approximately 9,900 ft (3,000 m). All three outings took place during a long cold spell; the average temperature on the descent was 15 F (-9 C). Due to lingering sunlight or waxing moonlight, I was able to skin up the resort without using the Byte. I used it for the entire ski down to illuminate my route.

The final four days of use occurred during two separate hut trips into the mountains near Aspen, Colorado. The elevation of both huts was near 11,000 ft (3,400 m) and we were fortunate to have mild weather for both. Most of the use took place inside the huts after dark. The Byte was used when reading, tending the fire, making my way to the outhouse, and finding my way to and from my bunk.

Field Observations

I have had mixed experiences with the Princeton Tec Byte so far. The majority of the time, it works very well. I estimate my usage at nearly 10 total hours with the headlamp burning. I have found the low setting of the white Maxbright LED to suffice for most tasks. It has worked great for reading, making my way around camp, and tending the fire. It seems to illuminate a reasonable size area and seems to be a good balance of illumination and power consumption. I admit that I haven't used the Ultralight Red LED very often. I have never used a headlamp with a red LED, so perhaps I'm just not used to it. I used it a minimal amount while car camping in Utah. After stargazing in my sleeping bag for a while, I used the red LED to check on the water level in a nearby pot for tea in the morning. It did seem to preserve my night vision. I have found that the red LED is next to useless if my night vision is not established. The setting in which I found the red LED the most useful was on the two hut trips. It was perfect for midnight trips to the outhouse without blinding myself or my hut-mates. It also provided just enough illumination to make my way without bumping into anything or knocking anything over. So far, this is my favorite use for this headlamp setting. I have regularly used the high setting of the Maxbright LED only when skiing down the resort after dark. While it isn't the brightest headlamp I have used, it produces an admirable amount of light for its size. It produces enough to illuminate a ski line and allows me to see far enough to plan several turns in advance. I definitely step my speed back, but I feel that I can ski at a reasonable and fun speed. The high setting of the Maxbright LED seems to produce too much light for any close-quarter tasks. For these, the low setting seems to be more than adequate.

Throughout testing, I have not had any problems with the pivot point. I have no worries about the Byte pivoting on its own, as it takes some force to angle it. I have found an angle that seems suitable for all close-quarters tasks such as reading, walking, etc and the Byte will likely stay positioned at that angle for ease of use.

As I touched on earlier, not all of my experiences with the Byte have been favorable. As I stated previously, my second, third, and fourth uses of this headlamp involved skiing down a local ski resort after dark in cold weather. During each of these uses, I returned to my car, took off the Byte, and depressed the power button to turn it off. Instead of turning off, the Maxbright LED strobed very faintly. Once this began, the headlamp would not respond to the power button. The only way I could turn off the headlamp was to remove the batteries. I thought that removing and reinserting the batteries would solve the problem. Unfortunately, the strobing resumed once I reinserted the batteries. The third time this occurred, the headlamp was still strobing 30 minutes later once I reached my home. I removed the cold batteries and replaced them with an extra set of batteries I had lying around; this seemed to solve the problem. Several weeks later, when packing for my hut trip, I tested the Byte by pressing the power button. It immediately began faintly strobing. I again replaced the batteries with a fresh set and the problem has not happened since.

Based on my experience, it seems that this issue is due to weak batteries, likely exacerbated by cold conditions. Unfortunately, this happened after only three hours of use of the included batteries. The second set lasted about the same, but I'm not sure that they were unused batteries. I am interested to see how long this third (brand new) set lasts. If the issue is indeed weak batteries, I am disappointed by the effect. When I have weak batteries in my other headlamps, the beam dims but is noticeable. The dim beam may not be ideal, but the headlamp is usable. With the Princeton Tec Byte, the faint strobing light renders the headlamp next to useless with absolutely no warning. I would be upset if I was relying on this headlamp for navigation in the backcountry and instead found myself with an underpowered disco ball.

Likes (so far):
low setting is great for camp tasks
red LED is great for maintaining night vision or not blinding companions

Dislikes (so far):
the battery issue is quite concerning and does not instill confidence

Long Term Report

Field Conditions

I have used this headlamp over 21 days during a recent whitewater rafting trip through the Grand Canyon in Arizona. It was primarily used around camp for cooking, reading, and general camp use. It was also used during a 40 mi (64 km) night float at the end of the trip. During this float, it was one of the headlamps used by our group to orient ourselves to the shore and to midstream obstacles. Elevations during this trip ranged from 3200 ft (980 m) at the put-in to 1200 ft (370 m) at the take-out. Weather was quite variable, and ranged from sun to thick clouds to strong winds to rain. Temperatures ranged from approximately 75 F (24 C) to 30 F (-1 C).

wearing the Byte

Wearing the Princeton Tec Byte.

Field Observations and Summary

Over the course of this trip, I came to fully appreciate the light output of this little headlamp. Around camp, I used the low setting almost exclusively, and it was the perfect brightness. It provided enough light to make my way around camp while avoiding cacti and other obstacles. Due to the short days, we were occasionally finishing dinner in the dark. When this occurred, the Byte performed well and always provided enough illumination for cooking tasks. I was especially pleased with the Byte on our night float. The high setting illuminated the far shores quite well and allowed us to determine when to adjust the course of the rafts. I didn't find myself using the red LED very often. In most circumstances, maintaining my night vision wasn't worth the risk of stumbling across a cactus in camp because of the decreased illumination. I did use it a few times when I didn't want to blind my companions, but I found myself turning on the low setting once away from them.

The pivot mechanism of the Byte continues to be quite sturdy. Unfortunately, I've found that I'm not able to easily adjust the angle with one hand; I usually have to use both hands. This is not a huge deal, but can be a little inconvenient at times.

Unfortunately, these positives continue to be outweighed by the negative. The battery life of this headlamp continues to be dismal. In addition to this short battery life, the faint strobing that occurs with battery failure is very frustrating. Shortly before I left on this trip, I conducted two tests. I fully charged quality, name brand rechargeable batteries and installed them in the Byte. I turned the Byte on to the high setting and walked away, checking on the headlamp periodically. The first time, I found that the Byte was strobing after only 10 hours. During the second test with a different set of batteries (although of the same brand), I found it strobing after 11 hours. This is a far cry from the 80 hours claimed by the instruction manual. (As a caveat, I now notice that the Princeton Tec website has been changed to claim a mere two hours of burn time on the high setting. Given the times I've found, I'm not sure where this number comes from.) As I mentioned previously, I primarily used the low setting when on my Grand Canyon trip. I estimate that I used the headlamp an average of 1.5 hours per day (primarily at night). Despite an estimated 15 hours of usage on the low setting, the first set of batteries died after 10 days. The second set also lasted 10 days with an estimated 15 hours of low setting usage and 3 hours of high setting usage. Again, this is a far cry from the 96 hour burn time claimed in the instruction manual for the low setting. When the batteries failed on the first night, the moon was not yet out, but the stars were relatively bright. The strobing did little to increase illumination, which made digging my spare batteries out of my drybag a chore. Fortunately, I knew exactly where my spare headlamp was and used it to find the batteries.

Given the high quality of light output from the headlamp, I would be willing to excuse the short battery life if it weren't for the faint strobing when the batteries die. With other headlamps I've used, it becomes obvious when the batteries are failing because the beam becomes dimmer. I haven't found this to be the case with the Byte. It seems to be all-of-nothing. This necessitates having spare batteries immediately accessible or else risking a nearly blind search for them. I feel that this is a poor design, and it makes me very nervous about using this headlamp. I have carried a spare headlamp everywhere for eight years, and I have rarely had to use the spare until I started testing this headlamp. The Princeton Tec Byte will go into my storage box and will likely only come out if I need an extra to loan out or need additional illumination. Regardless of the reason, I will charge the batteries in the headlamp regardless of how recently I have used it.

Significant illumination
Red LED is a great way to either preserve night vision or not blind companions
The pivot mechanism is very sturdy

The pivot mechanism often requires two hand to adjust it
Battery life has been very underwhelming
The strobing that occurs when batteries die renders the headlamp essentially useless
Battery failure seems to occur without any warning (such as beam dimming)

Thank you to Princeton Tec and for the opportunity to test this headlamp.

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Reviews > Lighting > Headlamps - LED > Princeton Tec Byte Headlamp > Test Report by Andrew Henrichs

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