The ArmyTek 120 day Challenge!!!

pjandyho

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I`ll place my bet that it fails between 100 and 110 days.
What makes you say that? Based on some expert calculations? Or just pessimistic guess work? I think even if it lasts 100 days it would be great enough. In a survival situation, you won't care if it lasts 10 days if you can't find food, water, shelter and fire.
 

Badbeams3

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What makes you say that? Based on some expert calculations? Or just pessimistic guess work? I think even if it lasts 100 days it would be great enough. In a survival situation, you won't care if it lasts 10 days if you can't find food, water, shelter and fire.

It`s a highly technical formula, based on the length of some hairs sticking out from my ears after a bath...very complex. Whats your bet?
 

subwoofer

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Past day 80 and right now 1931 hours of runtime.

In another thread about the lowest low, and the longest runtime, I mentioned that the Armytek lowest firefly is still a usable output level. There are lights that go lower and lights that have ultimately longer runtime (like the PAL light with 1-2 years), but they are not much use.

In the recent CPF-UK meet, we went into a mine and at one point switched off all the lights. It actually felt like someone was pushing on my eyes as the blackness was total. Switching on the Viking Pro I had with me on lowest firefly, and it was enough light to see by even after only 5 minutes of allowing our eyes to become adjusted. OK you wouldn't be running around, but you could see enough. To me this is pitched just right.

Day of
Challenge - Date
10 ---------- 19/05/2013 21:00 :thumbsup:
20 ---------- 29/05/2013 21:00 :thumbsup:
30 ---------- 08/06/2013 21:00 :thumbsup:
40 ---------- 18/06/2013 21:00 :thumbsup:
50 ---------- 28/06/2013 21:00 :thumbsup:
60 ---------- 08/07/2013 21:00 :thumbsup:
70 ---------- 18/07/2013 21:00 :thumbsup:
80 ---------- 28/07/2013 21:00 :thumbsup:
90 ---------- 07/08/2013 21:00
100 -------- 17/08/2013 21:00
110 -------- 27/08/2013 21:00
120 -------- 06/09/2013 21:00
 

Wiggle

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1500 mah typical for CR123
2100-3400 mah for 18650

2 CR123: 3V * 1500 mAh = 4.5 Wh * 2 = 9 Wh
18650: 3.7V * 3000 mAh = 11.1 Wh

These numbers are just an approximation, you'd need to do a proper "area under the curve" type assessment to get the more exact values but they are pretty close overall (especially a lower capacity 18650 around 2600 mAh). 18650 has the advantage of having a voltage closer to the LED Vf but will also suffer some self-discharge in this kind of time frame. I'd bet they come out quite comparibly.
 

bluemax_1

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2 CR123: 3V * 1500 mAh = 4.5 Wh * 2 = 9 Wh
18650: 3.7V * 3000 mAh = 11.1 Wh

These numbers are just an approximation, you'd need to do a proper "area under the curve" type assessment to get the more exact values but they are pretty close overall (especially a lower capacity 18650 around 2600 mAh). 18650 has the advantage of having a voltage closer to the LED Vf but will also suffer some self-discharge in this kind of time frame. I'd bet they come out quite comparibly.
Assessing it from a logical standpoint, if I were trying to conduct a maximum runtime test, why wouldn't I use the highest capacity battery available?

That would mean 12.2wh vs 9wh. I also don't really see much self discharge in my 3400's over a 4 month period. That and considering the efficiency of the buck circuit vs the 18650 being close to the Vf, I don't really see 2xCR123's beating a 3400? Are there some other potential factors I'm missing?


Max
 

Wiggle

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Without knowing exact driver efficiencies for 6V versus 3.7V it is hard to know for sure but I agree, my gut feeling is the 18650 (especially if it is one of the 3400s) would win out on overall runtime though the results would be not far off from each other
 

subwoofer

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So are you going to do this test with 2 x CR123s next? :)

I expect that you'd get longer runtimes with the primaries.

My reaction to that suggestion in pictures:

:eek:........ :crackup:....... :poof:


Though in all seriousness, there are actually a few variables that can be tried and some doubts I have had since starting this off.

These Predators all use 18650 as the default power source and as mentioned in the first post this is how this test is being run. However the default has a 2.8V cut-off, but we know that the NNP type 18650s which 3100mAh are, will still give power down to 2.5V.

For the new Viking Pro, Armytek have changed the default to the LiFePO4 (with a cut-off of 2.5V), not because they think you will use this type of cell, but because the newer high capacity 18650s will provide usable power down to 2.5V. The newer Predator Pros will probably go this way too.

The LiFePO4 power source has a cut-off of 2.5V, so to get the most runtime out of these 3100mAH cells I should have chosen that. Alternatively if I had chosen 2xCR123 as the power source, the cut-off is 2V, so this would effectively use the 18650's power right until the protection kicks in.

I did choose 18650 as the overall capacity should be higher.

Re-running the test....maybe if I get in the right mood:drunk:
 

Tiresius

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So far, the light's getting close to what they're claiming. Lets hope you don't have to fight the dust bunnies once this challenge is completed :D
 

subwoofer

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Day 90! - Now it is getting interesting. Previously my checks on the condition seemed to be an unnecessary formality, now I feel that the two checks per day are worthwhile.

There is no change in the relative brightnesses to each other or the reference Viking Pro.

No dust bunnies so far....

Day of
Challenge - Date
10 ---------- 19/05/2013 21:00 :thumbsup:
20 ---------- 29/05/2013 21:00 :thumbsup:
30 ---------- 08/06/2013 21:00 :thumbsup:
40 ---------- 18/06/2013 21:00 :thumbsup:
50 ---------- 28/06/2013 21:00 :thumbsup:
60 ---------- 08/07/2013 21:00 :thumbsup:
70 ---------- 18/07/2013 21:00 :thumbsup:
80 ---------- 28/07/2013 21:00 :thumbsup:
90 ---------- 07/08/2013 21:00 :thumbsup:
100 -------- 17/08/2013 21:00
110 -------- 27/08/2013 21:00
120 -------- 06/09/2013 21:00
 

pjandyho

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So far so good on the run time test.

I received my Predator Pro in warm flavor and have been very pleased with it.
 

Wiggle

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Thanks for doing this test. I was playing around last night with the lowest moon mode and was surprised how useful it can be with a diffuser in near complete darkness. I initially thought I had programmed a brighter moonlight by accident but confirmed my eyes had just adapted when I turned my Quark on to .2 lumen which was noticeably brighter.
 

subwoofer

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Day 100 has passed us by (was a bit busy so missed the day itself) and today there is still no visible change when comparing to the reference Viking Pro (which is not part of this challenge itself).

Which will go first? Theoretically the Predator v1.2 as Armytek have improved and updated their S-Tek Driver since it was produced, but it is still in there right now.

Day of
Challenge - Date
10 ---------- 19/05/2013 21:00 :thumbsup:
20 ---------- 29/05/2013 21:00 :thumbsup:
30 ---------- 08/06/2013 21:00 :thumbsup:
40 ---------- 18/06/2013 21:00 :thumbsup:
50 ---------- 28/06/2013 21:00 :thumbsup:
60 ---------- 08/07/2013 21:00 :thumbsup:
70 ---------- 18/07/2013 21:00 :thumbsup:
80 ---------- 28/07/2013 21:00 :thumbsup:
90 ---------- 07/08/2013 21:00 :thumbsup:
100 -------- 17/08/2013 21:00 :thumbsup:
110 -------- 27/08/2013 21:00
120 -------- 06/09/2013 21:00
 

WilsonCQB1911

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Do you think the test results would be different if one were to use the light intermittently on moonlight? As in, would one still get a combined total runtime of... whatever it is going to be... if turning the light off and on rather than using it continually for the 100+ days?
 

subwoofer

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Do you think the test results would be different if one were to use the light intermittently on moonlight? As in, would one still get a combined total runtime of... whatever it is going to be... if turning the light off and on rather than using it continually for the 100+ days?

That is a good question. I think if the light were turned on for 8 hours a day in one stretch each time you would probably get the full 'continuous' runtime out of it, but I have come across drivers that won't start once the voltage reaches too low a level, but if they were running already they will go to a lower voltage (therefore giving you a longer run). I don't know which of these will be the case with the Predator, and that is one test, I am not prepared to do :eek:
 

bluemax_1

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That and batteries seem to recover slightly from short intermittent use. There is another factor of how the driver circuit acts though, and it's related to what subwoofer mentioned about some drivers not being able to reignite a light that's been shut off when the battery level is too low, even though it was running fine before it was shut off.

The problem is if there's a potential for the driver circuitry to draw more power at turn on than it takes to keep the light running, in which case, turning it on and off more frequently may possibly flatten the battery faster than if it was turned on and kept on for longer periods.

This is all moot anyway. From subwoofer's tests, it appears the lights can live up to their claims of running continuously for 120 days, in which case, using the lights for only 8 hours each day, it would run for a whole year on one battery! If you used it only for the typical 4-5 hours per night that most people do in power outages (they just go to bed earlier), it would potentially run for 2 years.

I don't know about anyone else, but if I'm stuck in some kind of last ditch situation where I'm so unprepared that I don't have any additional batteries or a way to charge the battery I DO have for even 120 days, much less a year, I think I'm probably screwed.


Max
 

WilsonCQB1911

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Yeah, that's what was I was thinking of. I've seen lights that would keep going so long as you didn't turn them off, but once you turned them off, they wouldn't come back on if they were at a low enough level.

subwoofer, I'm just trying to help :nana:. You can do a CR123A test, a turn on and off test with 18650... and then one with CR123A. And then the second-lowest level... with all the above iterations.....

But regardless, as bluemax noted, this things has an incredible runtime in addition to all its wonderful features. I bought 2 cause I liked it so much and may get an XML version to boot.
 
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