I have shared that concern in another thread here in CPF. The spring in my D40A sits or is soldered in not exactly perpindicular manner. There is a slight lean off-center. When the body tube is screwed into the head with the batt-carrier inside, there is a big possibility that the spring will slightly creep away from the center of the batt-carrier and touch both + and - portions of the carrier, creating a dead short.
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I have shared that concern in another thread here in CPF. The spring in my D40A sits or is soldered in not exactly perpindicular manner. There is a slight lean off-center. When the body tube is screwed into the head with the batt-carrier inside, there is a big possibility that the spring will slightly creep away from the center of the batt-carrier and touch both + and - portions of the carrier, creating a dead short.
Lucky of you if your unit has the spring sitting dead on-center. That's why there is no spring-grating noise since it is turning in its own axis (and no creep away from the center of the batt-carriers + contact)
__philippe
Enlightened
Possibly an advantage to the manufacturer, who avoids a costly fabrication step for milling built-in cells channels within the flashlight body. On the other hand, there is the added cost of the carrier components themselves, so maybe, cost-wise, it balances out.
However, on the down-side from the user standpoint, a battery carrier introduces additional points of failure by multiplying the interfaces between the source of power (Batteries) and the sink of power (LED emitter):
Electrical drawbacks
- multiple contact points between carrier and cells, carrier and emitter, carrier and end cap, each induces minute but unwanted additional electrical resistance, detrimental to optimum current conductivity
- each additional interface point is more potential source for bad contact, or loss of electrical continuity altogether
- potential source of fatal short-circuits (as discussed above in this thread)
- need to be designed to prevent accidental polarity inversion
Mechanical drawbacks
- source of rattle inside the body
- structural integrity often marred by flimsy material choice (notwithstanding the remarkably sturdy D40A's carrier)
- increases flashlight overall footprint (diameter and length)
- increases flashlight weight
After this admittedly biased view on the subject, let's hear the real case in favour of battery carrier, anyone please ?...
Cheers,
__philippe
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__philippe
Enlightened
In my case, the spring in the head is only slightly angled off-center. It is not enough to produce any scratching beyond the inner centre of the carrier centre contact. Juding from the appearance of the carrier's contact, I would say the traverse of the spring is less than half the inner contact diameter. I certainly can't hear any scratching sounds, beyond the scraping of the threads themselves (and I agree with Bumble, the threads are dry as shipped).
I can see why people would think that a potential source of failure is the spring getting bent and stretched out during tightening - and possibly making contact with the positive contact plate in the head (thus causing a short once full contact is made with the carrier). Of course, that's theoretical at present - and any such short should show a clearly distended spring (which I don't see on that one posted pic of a shorted unit). Conductive debris in the head, or damage to the insulating ring in the head, could similarly be expected to cause a potential short. Again, all of that is speculation until an example is confirmed. In any case, I agree it is more likely that any potential shorting risk would come from the head and not the carrier, which appears to be exceptionally well made (compared to most carriers I've seen).
Carriers are common in lights with more than two cells, since they simplify the engineering. Of course, whether you use a carrier or have cut-out wells, the greatest risk is user error of accidentally reversing one or more cells in the sequence. This will cause a nasty short that will likely destroy your light/carrier (and your cells), not to mention potentially causing a fire. In that sense, I suppose one of the "benefits" of using a carrier is that any short will only destroy the carrier and not your whole light (i.e., the damage is immediate in a carrier, whereas a light would only be affected once full contact of the head is made). A dubious benefit I suppose ... but one that most people will probably wind up experiencing one day. Even with alkaline/NiMH, it's important to always pay careful attention to proper orientation when inserting multiple cells. :candle:
weekend warrior
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Got my D40 in the mail today. Absolutely love it! Feels great in the hand, and the UI is fantastic. It's nice always having direct access to turbo and moonlight from off, and the blinky modes are "hidden" but not "cycle through the regular modes 18 times" hidden. The buttons feel perfect too, not squishy, not hard either, the perfect amount of tactile feedback. Really happy with this light.
AmperSand
Enlightened
Did you also notice if you double click to turbo it doesnt retain turbo as the last used mode if you use moonlight It keeps memory of moonlight instead.
Ie. Use in moonlight mode, turn off with single click of power button.
Doubleclick power to jump to turbo.
Single click power to turn off.
Single click power to turn on once again, still in moonlight not turbo.
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Thanks for another outstanding review Selfbuilt!
I ordered my D40A pretty much right after reading your review and just received it yesterday.
The good- nice output, beam pattern, and tint (I have an Olight S65 which is very green in comparison).
The bad- spring in head is rather crooked/angled, fleck of anodizing is missing near knurling on battery tube.
One thing I noticed is that when the batteries run down from high for example, the light "steps down" its output from high to medium and then eventually steps down again from medium to low. It doesn't have a continuous decline in output like that shown in Selfbuilt's runtime graphs. Does anyone else's D40A behave like this?
I ordered my D40A pretty much right after reading your review and just received it yesterday.
The good- nice output, beam pattern, and tint (I have an Olight S65 which is very green in comparison).
The bad- spring in head is rather crooked/angled, fleck of anodizing is missing near knurling on battery tube.
One thing I noticed is that when the batteries run down from high for example, the light "steps down" its output from high to medium and then eventually steps down again from medium to low. It doesn't have a continuous decline in output like that shown in Selfbuilt's runtime graphs. Does anyone else's D40A behave like this?
Interesting ... what batteries are you running it on? And how closely were you monitoring the light when this occurred?
As you will see in my runtimes, alkalines tend to have a periods of relatively rapid drop, followed by slow declines. These could well appear as "step downs" if you only checked in on the light periodically during these phases. NiMH had smooth declines (although even at that, they do round out at the tails). Did you observe sharp drops in output?
Selfbuilt,
I used regular Eneloops (white, 2000 mAh). I was sitting in the room next to the light when each step down occurred. The change in output was very noticeable, which is what caught my attention as I was reading other light reviews on CPF
at the time. Eventually, I pushed the mode button to send it back to Turbo. It stayed there for a few seconds, the low power led started flashing, then it stepped down to medium and shortly after to low again.
Interesting .... that's exactly the behaviour I observed on L91 lithiums when they were fresh.Selfbuilt,
I used regular Eneloops (white, 2000 mAh). I was sitting in the room next to the light when each step down occurred. The change in output was very noticeable, which is what caught my attention as I was reading other light reviews on CPF
One possibility is that the step down is based on the initial charge state of the Eneloops. In my case, they were all fully-charged to start, and gradually run down. But I suppose its possible that if the light were started at a lower battery charge state, the light could have done actual step-downs (although I expect that would have happened within the first few seconds after activation). If I get a chance to test partially depleted cells, I'll let you know what I find.
weekend warrior
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When I put some weak eneloops in mine and turned it on to turbo it would only light up briefly before stepping down to high, or what I assumed was high, I didn't measure. I didn't leave it on long enough to drain the batteries anymore then that so I didn't see it stepping down to medium or low.
AmperSand
Enlightened
Mine exhibits some strange behaviour when cold on moonlight mode.
It will have a very, very noticible flicker.
Turn it on turbo to warm it up somewhat and the flicker on moonlight disappears.
Also noticed if it's warm after it has been in my pocket its ok also.
Anybody else had any similar behaviour?
It will have a very, very noticible flicker.
Turn it on turbo to warm it up somewhat and the flicker on moonlight disappears.
Also noticed if it's warm after it has been in my pocket its ok also.
Anybody else had any similar behaviour?
yes mine does too, its temperature dependant on when the moonlight will actually flicker. if it flickers and as you said... if you warm the light up a little it stops... BUT also if you cool the light down it stops. most strange. NO other modes seem to flicker at all regardless of the temp of the light.
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I haven't noticed any flicker on Moonlight on my sample, at any temperature. But I have noticed on other lights that flicker effects can sometimes occur on moonlight modes (I gather it is hard to stably tune every circuit down to those levels).
I've a Quark 2AA Turbo, Quark AA Regular and Quark AA Tactical, and all of them flicker at low mode (the second mode), but it only happen when using 1.5v battery, 3V and 4.2v battery are ok. Contacted the manufacturer here in china directly and they tried all their Quark on hand and they all flicker, some at different mode than mine.
From their reply, give me the impression that they do not has the intention to fix it. So I returned the 2 Quark AA and keep the Turbo since the Turbo will not flicker when using 2AA which will be exceeding 1.5V. So I believe what Selfbuilt said about flickering. What I don't understand is why didn't they do anything about it, since there are some manufacturer who do not has this problem. And I believe this will hurt their business quite badly.
And the ironic thing is: The two different dealers that I bought the light from, continue to sell the light at the same price, even after they knew about this problem.
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That's peculiar ... I've never notice any flickering on any of my Foursevens lights.
What you are describing is different from moonlight flicker (which results from trying to tune a particular constant-current circuit too low for a stable current). In those cases, apperance of flicker is idiosyncratic - some lights show it (consistently) but most lights never do (consistently). In cases of persistent flicker, I would personally return for a replacement/repair. One manufacturer actually managed to re-tune a particular light and ship it back to me once, to resolve this problem.
But the consistent appearance of flicker at specific drive levels and input voltage (across multiple lights) suggests that one of the common circuit components is not able to consistently meet its rated specs. I have seen this occur several times (usually on new model launches). The usual response from the manufacturer is to isolate the problem and find a different supplier for the affected component, to ensure consistent quality. This can sometimes take a little while to isolate, as the fault doesn't show up in every unit (and may not be caught by stand QC processes, which don't test every light on every voltage source and level). But it would indeed not be a good business practice to ignore it.
In this case, I suggest you contact Foursevens directly in the US. It is generally not up to the manufacturing plant to resolve these issues on its own - that typically comes from a directive from "head office", so you should really let them know of your issue. Good luck!
Mine is not the common PWM flicker. in fact It has a very subtle flicker as if when contact point or screw thread is dirty. I try to clean all contact point and screw thread and re-lube it and problem still persist. And when contacted the manufacturer, the engineer even assemble a new unit for testing. And the only reply is: "We tested on our side and we have the same flickering problem, and we have no idea what is cause".
Out of curiousity, I've checked online and found there numeral reports about flickering problem with Quark AA at different mode level, and some of them even dated back to 2010. Here is one of them:
1) http://www.candlepowerforums.com/vb...Quark-123-2-problem-with-barrel-thread-length
2) http://www.amazon.com/dp/B00513DDMS/?tag=cpf0b6-20
There are even more cases but I just have to find it again. Some of them contacted 4sevens and all 4sevens do is change the switch and the problem didnt go away. So I am sure 4sevens knew about the flickering problem 3 years ago, and they still didnt fix it in my new unit, which was produced after their so call "rebrand" campaign. And beside the flickering issue, the pre-flash is still there, in all my Quark light. So.... really dont know what to say.
I didn't contacted 4sevens directly because I am currently located in China, and if the manufacturer here cannot fix it, I don't think there is anything 4sevens can do from US. And beside that, there are other brand and model I can get here, so even though I really like the mode spacing and runtime of this light. I just returned the light, and never look back.
Note: If all your Quark do not exhibit the same flickering issue, I suspect that the manufacturer may be using the old batch of drivers which was rejected by 4sevens and sell it here in China. Since all the Quarks here (Not Quark Mini) from both manufacturer and dealer are having flickering problem. And yes, the dealers here tested every single one he have in stock and they all flicker, even the one assemble by the engineer himself.
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