Brief review of Duracell Daylight 2AA LED light

[mattchase]

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Updated 11-12-08: I have re-run all of the tests to double check accuracy. Once again, at almost the exact same time, the logging program crashed. However this time I had been making screen captures of it so I still have a mostly complete graph to post.
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Testing was done with 2AA Eneloops with the light at 1 meter.



This is the last screenshot I took before the program crashed, the flashlight was still putting out about 80 lumens but was dropping at a steady rate (the output started at about 1000 lux (corrected!)).

Direct Meter Readings
1802 lux peak (spot) @ 1m
746 lux peak (wide) @ 1m


Lightbox Readings (QUPS): I have done this test more times than I can count, with 3 sets of batteries (eneloops and alkalines) and I am getting two different sets of numbers from just a fraction of an inch difference in light position. I believe I am holding the light straight up and down and in the center of the milk carton light box, but it seems the smallest twitch changes the peak recording by about 35%. I have even tried attaching the light to a tripod center post, pointing straight down, to make sure the light is not tilted towards or away from the center of the light box. In that position I am getting the lower numbers similar to my initial testing. I need to make a new light box to tighter tolerances for small flashlights, I have tested some big lights with this one and the hole on the top is a bit large for smaller lights like this leaving room for error, which I think is what I'm experiencing now. So I present to you both sets of numbers that I am able to repeat, I'm not sure which are more accurate so don't hold me to them. If / when I get a new milk carton light box I will test again.

3711 lux peak (spot)
3994 lux peak (wide)

5960 lux peak (spot)
6008 lux peak (wide)


In the field experience: I took a bike ride last night with a Coleman Cree on one handlebar and a Duracell Daylight on my other handlebar. With them pointed equally at about 8 - 10 feet ahead of me I prefered the Duracell. Even though it is not as bright overall as the Coleman and has very little spill, the center bright spot on the Duracell is larger so covers more area with more light compared to a small bright spot with a large but dim spill.



Beamshots (at about 2' from wall):

Fenix P1 (rcr123) - Duracell 2AA Wide (eneloop) - Coleman 2AA Cree (eneloop)


Fenix P1 (rcr123) - Duracell 2AA Wide (eneloop) - Coleman 2AA Cree (eneloop)


Fenix P1 (rcr123) - Duracell 2AA Wide (eneloop) - Coleman 2AA Cree (eneloop)


Fenix P1 (rcr123) - Duracell 2AA Spot (eneloop) - Coleman 2AA Cree (eneloop)


Fenix P1 (rcr123) - Duracell 2AA Spot (eneloop) - Coleman 2AA Cree (eneloop)


Fenix P1 (rcr123) - Duracell 2AA Spot (eneloop) - Coleman 2AA Cree (eneloop)



As for build quality it is neither bad nor great. Time will tell how well it will hold up to actual use, though in my case it is probably going to end up on my bike so won't be getting dropped or handled very often. The beam has rings in it at the spot setting which are noticable on walls but not really a problem in real world use, and at the wide setting the beam is pretty smooth all the way around. There is a noticable difference in the center spot size and brightness from the spot setting to the wide setting, though not as big as the meter readings above might make you think. In doing some medium distance testing (about 25') I can see that on spot there is a better concentration of light and it is a bit brighter than on the wide setting. At about 60' the light still does an ok job but is starting to struggle. Pointing it at the side of a building about 90' away I really couldn't tell if there was any more light on the building, maybe just a bit with the light set to spot. There is some ambient city light around me affecting this result, out in the wilds this light would likely be more effective at such distances. But don't buy this light expecting a lot of throw, as it just isn't there.

But that's ok with me...it works great on my bike and looks pretty cool too.

 

[cybersoga]

Thanks, for a similar price in the UK I can get a Fenix PD20 which does 180 lumens for 2 hours, which is going to be much better for throw, but this duracell daylight has an interesting wide beam and battery life seems pretty reasonable...

 

[HitecDrftr]

In response to the questions from another thread, I have done some testing with this light today. I was working on a runtime test but unfortunately after about 4 hours the light meter software froze, so I have no recorded data to show the output over a period of time. I was keeping an eye on it during those 4 hours so have a pretty good idea of the flashlights performance, I just don't have a graph to back it up. Testing was done with 2AA Eneloops charged this morning, with the light at 1 meter.

Lightbox Readings (QUPS):
3711 peak (spot) = approx. 51.5 lumens
3994 peak (wide) = approx. 55.5 lumens

I appreciate your testing of the 80 lumens (rated)2AA Duracell Daylite.
I would be very interested to see your results using the stock Duracells that come with the light. MrGman ran a test of the 80 lumens 3AAA Duracell Daylight using both rechargeables and the stock cells in his integrating sphere:

Duracell Truebeam Wide______74__________________3AAA Akalines_______---------------------------------,
Duracell Truebeam Wide______64__________________3AAA NiMH _________--------------------------------,

the 74 result is 92.5% of the manufacturers's stated lumens, while a 64 is only 80% of stated lumens. Big difference. Remember also that with any instrumentation there will be some margin of error, though with an integrating sphere, the error would undoubtedly be low. Realize also that a light meter is no where near as accurate as an integrating sphere, ESPECIALLY when looking at floody lights. (IS is orders of magnitude more accurate, as well as orders of magnitude more expensive.)

Here are MrGman's IS numbers. I have added columns for the manufacturers stated lumens and the percentage of stated that was actually achieved. These are the only "Stated" numbers I could find. It would be great if we could round out the list (anyone care to help?)

Food for thought- If you decide to use your preferred battery of cells, the manufacturers suggested cells should be considered as a reference.

Thanks for your work. :thumbsup:

Hitec

 

[mattchase]

Updated first post.


Still wish I had an integrating sphere...

 

[csshih]

the output started at about 1000 lumens

woah.. that is some bright light.

 

[Marduke]

I think (hope) he meant lux