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Reviews > Lighting > Headlamps - LED > Princeton Tec Byte 2011 > Test Report by Ralph Ditton

Princeton Tec Byte Headlamp
Test Series by Ralph Ditton
Initial Report : 14th June, 2011
Field Report: 12th September, 2011
Long Term Report: 18th November, 2011

                                                                 Byte Headlamp
                                                                                                               Byte headlamp
Personal Information
Name Ralph Ditton
Age 59
Gender Male
Height 1.76 m (5 ft 9 in)
Weight 74 kg (163 lb)
Email rdassettsAToptusnetDOTcomDOTau
Location Perth, Western Australia. Australia

Backpacking Background
My playgrounds are the Bibbulmun Track, the Coastal Plain Trail, Darling Scarp and Cape to Cape Track. I lead walks for my bushwalking club and they consist of day walks and overnighters. My pack weight for multi day trips including food and water, tends to hover around 18 kg (40 lb) but I am trying to get lighter. My trips range from overnighters to six days duration.

Product Information
Manufacturer Princeton Tec
Year of Manufacturer 2011 (Made in China)
Model Byte
Colour White
Lamps 1 Maxbright LED
1 3 mm (0.12 in) Ultrabright Red LED
Beam Distance Maxbright - High - 30 m (98 ft)
                   Low - 15 m (49 ft)
Red Ultrabright - 6 m (20 ft)
Brightness Maxbright - 35 Lumens
Red Ultrabright - Not stated
Burn Time Range 2 to146 hours
Listed weight 64 g (2.25 oz) incl. headband & batteries
Measured weight 60 g (2.11 oz) incl. headband & batteries
Water Resistant Yes. Level 1
Batteries 2 AAA Alkaline or Lithium
2 AAA Rechargeable NiCad or NiMH
Warranty International - USA
5 year Warranty
MSRP US$19.99

Product Description
The lamp and components arrived in a card and blister pack. The headband and batteries were in separate blisters on the reverse of the card.

The batteries supplied with the headlamp are two 1.5 Volts AAA Duracell Alkaline MN 2400 manufactured in the USA.
There is a mixture of English and French on both sides of the card, however the instruction sheet is in English, French and German.

What I received physically matched my expectations from the manufacturer's web site.

This headlamp is tiny and weighs a paltry 60 grams (2.11 oz). My headlamp is lighter than the advertised weight of 64 grams (2.25 oz).
The actual headlamp is attached to the bracket which the headband feeds through by way of an asymmetrical single arm bracket. The headlamp can rotate through this arm bracket to the desired light angle for whatever task is being undertaken. The up angle is around 45 degrees and the down angle is around 75 degrees.

The On/Off switch is a rubberized pad that has 5 raised dots (3 at the back, 2 at the front) on it and is shaped like a car door. My index finger pad just about covers it. It is just a matter of pressing on this pad to scroll through the various light settings.

The red light source always turns on first, followed by the two settings for the Maxbright LED. (Low then High).

At the business end, there are two LED light sources. The 3mm (0.12 in) red LED is on the right and the Maxbright LED is on the left.

Access to the battery compartment is on the left hand end when facing the headlamp. To open it is just a matter of popping the door latch over the catch and rotate the door open. Just reverse the action to close the door.

Underneath the main light source there are another 5 raised dots in a similar pattern as mentioned above. They are there to assist with finger grip when adjusting the tilt of the light.

Level 1 Water resistance according to the manufacturer is the rating for splashing and quick dunkings.

Initial Impressions

As I have been asked to retest an updated model, I was unable to pick out any physical difference from the initial headlamp. The change must be internal and there is no way of physically examining this as the unit is sealed.

The headband is still made out of a soft elastic type material that feels furry to the touch. Adjustment of the headband is easily accomplished by threading the headband through the buckle to the desired head size.

Fitting the headband to the headlamp is just a matter of easing it through the side gates that are part of the asymmetrical single arm bracket.

This headband is quite comfortable on my head.

The manufacturer has added  a + and - on the inside of the battery door to assist with the polarity of the batteries. This was absent from the previous model.

Scrolling through the various light settings is still the same as before which is mentioned above. There is still no facility to turn the unit off by holding down the Mode Switch for a few seconds.

Aesthetically, this unit is still very attractive to me. It catches my eye.

Some Early Observations
Again, I carried out some brightness measurements using my Light Meter with  the new fully charged batteries. I know the batteries are fully charged because I tested them on my Battery Tester.
I did this at night in a totally dark room.
The units are expressed as "Lux".
The table below explains what a "Lux" illuminance is equivalent to:
0.01 Lux Quarter moon
0.27 Lux Full moon on a clear night
1 Lux Full moon overhead at tropical latitudes
50 Lux Family living room
100 Lux Very dark overcast day
320-500 Lux Office lighting

I will refer to the light simply as, Red, Low and High as they represent the Red Ultrabright LED and the Maxbright's two settings of Low and High.
The distance will be 2 metres (6.5 ft) as the manufacturer in their "Operating and Maintenance Instructions" sheet state: "Princeton Tec calculates total burn time as the time it takes for the light source to produce a minimum of 0.25 lux at 2 metres. 0.25 lux is about the equivalent of a full moon on a clear night."

My table above has 0.27 lux, so it is very close.

The table below are readings using new batteries that are fully charged.
Distance Colour Lux
2 metres (6.5 ft) Red

According to the manufacturer's web site, the following burn times should be achieved before diminished battery power produces enough energy to generate 0.25 lux of illumination:
146 hours
96 hours
2 hours

After the above times have been exceeded the headlamp should no longer be able to achieve the 0.25 lux.


I am looking forward to see if the manufacturer has fixed the burn time to achieve close to what is stated in the above table.
I tend to scroll through the various settings of a headlamp and use different settings for different tasks. I do not leave a headlamp on one particular setting in the course of a night.
I do however tend to use the low setting of a Maxbright LED the most as I do not want to blind my camping friends when talking and socializing with them.

The other bad habit that the previous model had was that it died without any warning. The only way to turn off the very dull light was to remove the batteries. Hopefully, this has been fixed.

Field Report
Since receiving this new version headlamp, I have used it at home in short bursts totaling about an hour. I used it to check on my Weber when cooking at night. There is no light source where the Weber is set up.

I took the headlamp out on the Coastal Plain Trail for two nights where the average nightly temperature was around 11 C (52 F). The headlamp was switched on around 6 pm as it gets dark then and was left on in various modes until I went to bed around 11 pm each night. That is a burn time of 5 hours each night.

The batteries were the ones issued with the headlamp which are alkaline.
I used the red mode for a short time just to try it out when I was searching for cooking items in preparation for getting tea ready. I found that I was able to see  reasonably well for the task that I set it.

The High mode was used when I went down the track to check on my tent as it rained both nights, and when I attended to nature calls.
By far, the majority of time the headlamp was in the Low mode. I used this mode to cook with, play dice and have a chat to my camping mate.

On the second night whilst playing dice after having turned on the headlamp some three hours earlier, I noticed that the light had dimmed quite substantially and there was hardly any difference between the High and Low modes. I still could see the dice but the circle of light was much reduced and dimmer so I changed the batteries.

I estimate that I got around nine hours out of the batteries with the majority of the time in the Low mode.

The batteries that I replaced them with were Ni-MH rechargeables. I immediately noticed an improvement in my light source.

Two days after returning home, I reinstalled the low alkaline batteries into the headlamp so that I could measure the light output. My battery tester had the needle in the yellow "Low" sector but hovering on the edge of the red sector "Replace".
I found a curious outcome. The batteries seemed a bit brighter after a few days rest and I could detect a slight difference between the Low and High settings. This has caused me to leave these batteries in a bit longer and see how they perform. I have put aside the rechargeable batteries and left them in their current state. The battery tester still shows them in a "Good" state after two hours of use.

The table below shows what my Light Meter recorded with the supposedly flat batteries after nine hours use.
The distance was 2 metres.
9 hours
0.3 lux
9 hours
14.6 lux
9 hours
15.5 lux

As can be seen from the table in the Initial Report, there has been a substantial drop in lux after nine hours of use.

Around a week later I had cause to use the headlamp at home on a dark side of my home. There is no outside light source.
When I turned on the light I noticed that there was no Red beam. I then scrolled through the  Low and High settings. I could not detect any variation between the light intensity.
Taking the headlamp off my head, I scrolled through to the Red setting. What I found was that there was a very tiny red square of light deep in the body of the lens. No beam was emitted.
I then carried out a series of measurements of lux readings at various distances; they being 2 metres (6.5 ft), 1 metre (3.3 ft) and metre (1.6 ft).
2 metres (6.5 ft)
.00 lux
0.5 lux
0.5 lux
1 metre (3.3 ft)
.00 lux
2.2 lux
2.2 lux
metre (1.6 ft)
.00 lux
4.3 lux
5.6 lux

The lux readings for the Low and High settings are very small. That is why I was unable with my naked eye to notice any difference between the settings.
Two nights later I went to use the headlamp and I got no light from any settings. The batteries had died. I tested them on my Battery Tester and the needle was 4/5 into the red sector of Replace/Recharge. They were definitely dead.
This time when I switched the headlamp on there was no frozen light in one setting that would not turn off by scrolling through the settings. This happened with the first version of this lamp. There was absolutely no light at all.
I then returned to the partially used rechargeable batteries and inserted them into the headlamp.
The headlamp got a lot of use around the home, especially when I was up on the roof trying to fix my TV aerial and doing my usual  cooking on the Weber.

A few nights ago I had to get back up on the roof to recheck the aerial and the batteries were dead. The last time I used it, the light source was fine but this time there was absolutely nothing. No warning such as fading brightness. I put this down to the nature of the rechargeable batteries.

To date I am happy with the performance of the headlamp. I am not getting anything near the burn time for the "Low" setting of 96 hours as advertised. In my initial report on version one of this headlamp, I did achieve 85.75 hours on high. This was achieved by leaving the headlamp on till the batteries went flat and not scrolling through the settings. I suspect this is the basis for the same claim for the "Low" setting. Whilst technically correct, it is a bit of a nonsense because no backpacker leaves their headlamp burning continuously during the days and nights till the batteries die. I am please that when the batteries died, there is no freezing of the light source when trying to scroll through the settings to turn it off. The headlamp's switch responds to being pressed now when the batteries are at the end of their life.

Long Term Report
In this phase I spent three nights at Gelcoat in the Wellington Dam Reserve and two nights in the Melaleuca Reserve, where the soil is sandy and the trees and shrubs have oil glands in the leaves. Species such as Banksia and Eucalyptus were in abundance.
Night time temperatures ranged from a high of 16 C (61 F) to a low of 7 C (45 C).
Elevations ranged from sea level to 80 metres (262 ft).

Prior to going to Gelcoat, I had been using the headlamp around the home on a very regular basis when doing the evening BBQ. The batteries were the rechargeable Ni-MH of 1.2 V with a minimum of 550 mAh.

On the first night I used the headlamp to cook with and find my way around the camp. There were ten of us in the group. In the very early hours of the morning I had to go on a nature call so I used the red light. I found my way along the path, through the covered section where we had pitched a tarp to protect food and cooking gear and the path beyond to the drop toilet. I returned using the same red light.

The following night I did much the same, however, using the red light I could not find my way through the camp to the toilet as I could not make out the path. I kept wandering off to the left. In the end I switched to Low and found the path. On my return I tried the High and found that I could not tell the difference between the Low and High settings. I did have difficulty in negotiating the uneven path. Time to change batteries. I did so inside my tent as I had a spare headlamp for emergencies.
I changed the batteries to non-rechargeable Alkaline MN2400 that had an output of 1.5 V. The difference was immediate.

The third night after using the Low setting to cook my meal, I used the red light extensively and was able to find my way around the campsite without any difficulty as the batteries were fresh. I even read a chapter of my book in my tent using the red light. I got up around 12.30 am because it started to lightly rain and I moved gear under the tarp. I did not want to disturb the other parties in my group hence the red light. Unbeknown to me, the next morning I had been seen by a fellow camper who was attending to  a number one nature call close by to her tent. She saw my red light from approximately 40 metres (130 ft) away.
She said that the bird group that she does volunteer work with use red light so as not to ruin their own night vision or blind the birds when spotting them. She was most impressed with me using the red light to move gear out of the rain. Mind you, she did not offer to give me a hand.

When I got home I tested the rechargeable and non-rechargeable batteries to see what the discharge was against my Light Meter over two metres (6.5 ft).
The non-rechargeable batteries had been used for approximately 6 hours and I estimate that the rechargeable batteries had been used for a combined time of 12 hours on mainly the Low setting with some Red settings. I hardly ever used the High setting as I was trying to get the most out of the batteries.
I must point out that the rechargeable batteries were not flat. They still had a charge but were in the "yellow" band of "Low" on my battery tester.

Rechargeable Ni-MH
Burn Time approx 12 hours
1.2 V
550 mAh
Distance 2 m (6.5 ft)
0.3 lux
2.1 lux
3.7 lux

Non-Rechargeable Alkaline Copper Top
Burn Time approx 6 hours
1.5 V
Not stated mAh
Distance 2 m (6.5 ft)
0.9 lux
27.9 lux
60.1 lux

A conservative rating for a good quality alkaline-manganese dioxide battery has a capacity of 1,000 mAh giving a typical drain of 10 mA. mAh stands for milli Ampere hour. It is a measure of a battery's energy storage capacity. mA stands for milliamps. It is the draw per hour. If I left the headlamp on continuously then I should get 100 hours of life out of the Alkaline batteries. I did achieve 85.75 hours in my first test of the first version of this headlamp at home, but no backpacker leaves their headlamp on continuously when out in the bush.
Speaking to my battery man at Battery World he stated that a Duracell Copper Top AAA battery should have a mAh of 1,300 and when used in a headlamp on the low setting you could expect it to last about 7 hours. When used in a stop/start fashion during the evening and following days, the draw on the batteries would appear to be around 186 mA. The manufacturer of this headlamp does not advise what its circuit draws from the batteries per hour. I wrote to the manufacturer to find out but they declined to offer a figure as it was "propriety".
For the rechargeable Panasonic battery the mA is about 91 per hour.
Another factor I need to be aware of regarding battery life for Alkaline batteries is their shelf life. How long has it been sitting in the shop? They do have a long shelf life of up to 5 years but they do degrade over time. The fresher the battery the longer life I will get out of it. I do look at the expiry date. Mine expire in March 2016.

I then used the Alkaline batteries at the Melaleuca Reserve over two nights and I mainly used the Low setting whilst playing dice with my friend. Burn time was approximately 8 hours over the two nights.
I have not been camping since, however, I used the headlamp around the home especially when cooking outside.
One little aspect that I used the red light source for was to pick up caterpillars eating my tomato plant leaves. The red light shows them up brilliantly. It makes it easy then to pluck them off the plant and feed them to my pet Huntsman spider.

The giveaway that the batteries are running low is when the Red light does not illuminate. All that I get is just a red spot inside the headlamp without any illumination. Scrolling through the Low and High settings I cannot tell any difference by my naked eye as they are very close in intensity.
Here ends my test of this headlamp.
I will continue to use it out in the field and around the home.

Thanks to Princeton Tec for making this headlamp available for testing and to BackPackGeatTest for liaising with the manufacturer.

Read more reviews of Princeton Tec gear
Read more gear reviews by Ralph Ditton

Reviews > Lighting > Headlamps - LED > Princeton Tec Byte 2011 > Test Report by Ralph Ditton

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