I am running a side-by-side temperature test with Nitecore EA41 now.
Quick Result:
Interesting, thanks for doing this. Is that 54C hot spot where the pill contacts the body? I presume so.
Judging from your tests, it seems the heatsinking isn’t as good as the EA41, but doesn’t appear too bad.
Any way to measure the temperature of the pill, or the base of the driver right after you unscrew the head? (And compare it to the EA41.)
Is it possible to disassembly the switch? I can’t get it out to reassemle the switch wires. :cry:
Is it glued, screwed or pressed?
I tried with a wrench and couldn’t get it rotate.
I think it is glued pressed
Man I wish they put abit more engineering thinking about these things to make easier to mod and generate more sell
This is a bit strange, as if Crelant bought the design or OEM manufactured this light, because all other Crelant lights have excellent thermal path to cooling fins, the part where LED sits is made from one piece of aluminium…
I got my V4A in today (ordered the neutral one and it looks 5000K-ish to me), and I quite like it, a tiny bit chunkier than my SWM D40A but its smooth reflector produces a nicer beam IMO, a nice distinct hotspot (slightly yellow in the middle as happens a lot with the XP-L Hi, but much better than some other lights that I have with Hi’s in them), around the spot a fairly bright and useful corona that smoothly fades into the spill.
The UI is very simple and I like simple: from OFF one click to the first adjustable brightness, another for the second adjustable brightness, another for OFF. I like starting in lowest then brightest so that is how I have set it by ramping the two levels, they are memorised until you break contact with the batteries (default is high first 
). I don’t like blinkies so it is good that it is not in the normal sequence. Can’t see any PWM, must be a high enough frequency.
I measured the lowest possible setting at 20 lumen, the highest 850 lumen (on freshly charged Eneloops 30 seconds after switch-on). If you only have one low setting like this light I think 20 lumen is a nice brightness, but of course there should have been an option for going lower than that.
It is great to have a bright flashlight again that runs on Eneloops, I have the SWM D40A but I can’t use it because it is my reference light for light measurements and have to keep it pristine. Too bad that this V4A has a suspicion of bad heat management (but hey, it works! 
), and the UI is ok but not great, as a low-to-high fan I will have to re-adjust the levels every time I switch batteries (so no lock-out for me, I hope the parasitic drain is not too much).
If it proves to be a robust light, for the price payed I’m perfectly happy with it 
Although the heat sink path could have been much better, it may be adequate for stock current levels. Has any simultaneously measured light output, host temp, and current? If light output drops significantly out of sync with current consumption, then there is a problem. Especially, if the host is not also heating up during the drop. Personally, I will just mod the light if that is the case.
The output on highest setting drops in the first few minutes, but stays over 85% of the output at 5 seconds. That 15% drop is not just heat but also a little bit of battery sag/drain.
I’m not at all worried.
I measured the parasitic drain of my V4A when the light off and not locked out at 0.77 mA. So it will drain my 2000mAh Eneloops in a bit over 3 months. Not too bad if you realise that NiMh cells do not become dangerous when fully drained, just annoying to have to remember either to lock-out the light or to charge the batteries in time before use.
(for who wonders how I measured it without frying the DMM: separated head from battery part, connected the head and tail shell (batt-) with a test lead, connected the batt-plus spring to the plus-pad on driver with two connected test leads, clamped the DMM on micro-amp setting from batt-plus spring to driver-plus pad too, parallel to the two connected test leads. So now head and battery part are fully connected (and thus this weird light is switched on) while the DMM is bypassed. Click the switch untill the light is off, disconnect the two test leads so that the current is diverted through the DMM)
Edit: measured the current of the lowest (20 lumen) and highest (850 lumen) setting too, resp. 60mA and 3.6A. These measurements were done with thick short test leads connecting head and battery compartment, and a clamp meter.
So the runtimes for the highest output will be a bit over half and hour (but longer because the current and output will certainly not be flat with this simple double-FET driver), for the lowest output you will have 33 hours.
Thanks for the measurement.
That’s a pretty high parasitic drain. I’ve measured parasitic drains on my lights from a lowest of 2.4uA (Zebralight SC5w), to the highest of 60uA (Sunwayman D40A). Your 770uA is more than 10x what the comparable D40A (4xAA light) uses.
In fact, I measure the Zebralight SC5w to use only 780uA to power its lowest moonlight mode, and that’s on just 1 AA cell. So the V4A uses 4x that power when idle.
I think this is a light that I will definitely lock-out when not in use. But that’s not really an issue for me, because I plan to mainly use it on high. Hopefully, it locks out with only a quarter turn or so.
Lock-out is just a fraction of a turn, but too much and the contact is recovered (which will directly switch the light on so you will not do that by accident). Not really figured how it works mechanically yet.
Doing some testing on mine now.
Immedion nimh
Ceiling bounced lumens:
1219 - 234
Not too shabby!
10 min test
0 - 1219
5 - 997
10 - 899
Very hot after 19 min!
I dare you to touch the spring attached to the driver 
True, but every time you lockout it resets the mode settings I configured (unfortunately it´s default high->low and now vice versa…)
K.
With 4AA NiMH batteries it should be over Vf the entire run time, so why would the output not be flat? Or are you saying it lacks any sort of current regulation? How are the FET’s controlled?
Wow, 3.6 amps sounds high for a 1000 lumen (or ~850 lumen) light, running from 4 Eneloops. Are you sure that’s correct? Have you tried a run-time test, to confirm?
The Sunwayman D40A (another ~1000 lumen 4xAA light), uses about 2.2 amps on max (maybe a bit more as the cells drain and their voltage drops).
I’m just guessing but I’m by no means an electronics geek, from the pictures it looks like a very simple driver with two tiny FETS in parallel, with a limiting resistor in series, controlled by a MCU that does all modes and ramping by PWM. But anyone more knowledgable could easily correct me on this.
Well, that would certainly explain why you see an output decline in the first few minutes, as your battery voltage drops.
However, this post claims that PWM isn’t used. I guess that could be wrong, and your testing seems to indicate it is wrong. Can you detect any PWM on lower modes with a camera?
Edit: Hmmm, I guess that post says no visible PWM. So, I guess it does use it, but at a high frequency. Oh well, I plan to use it mainly on high, so there won’t be any PWM there anyway.
This reminds me I need to stop buying lights before there are reviews.
Just received mine, and am very happy with the light. OTOH, why in hell would any decent flashlight manufacturer include a lanyard that can NOT be attached to the flashlight? I have plenty of other lanyards so I can figure out one that will work, or I will attach a large split ring, but WTH?