Crelant V4A

I got mine neutral white Crelant V4A the other day and put batteries in it tonight to try it out. I’m not exactly sure I’d call it neutral. It’s not cool white, but it decided more cool than a Nichia 219B. The lockout is quite iffy. If you loosen it a small amount to lock it out and than shake it or tap it will turn itself back on. I certainly wouldn’t suggest putting it in a bag with the expectation of the lockout working. This wouldn’t be that much of an issue if didn’t default to on in high when the circuit was completed.

It also has a bit of a donut hole in the center of the hotspot and there are rings in the beam. It should have had a LOP reflector instead of a smooth one.

To me it seems like a light with promise, but a flawed execution. I don’t see myself really using it.

When you say ‘donut hole’ do you mean a dark spot in the center or are you referring to the slightly blueish ring around the hotspot?

I mean a dark spot in the center.

Out of curiosity, is the hole always present or just at certain distances? My Courui has an odd donut hole on a wall at 4 ft but at 12 ft it’s gone. Is the emitter centered? Is the reflector seated properly on the spacer? Any obvious flaws or dark spots on the emitter?

I see no hole with my sample, just a bright hot spot, and the beam is not ringy unless you put it close to a wall.

Well, the dark spot in the hotspot in visible at 16+ feet from the wall. Everything looks centered & seated, and I don’t see any dark spots on the emitter.

Well, when it gets dark I will post a picture or two, but there is definitely a dim spot in the center of the hotspot, and the beam is definitely ringy on mine.

Also, after looking at it closer it’s apparent the the threads are not how the light makes electrical contact, so there really isn’t an electrical lockout. At best you can find a small spot where the batteries aren’t quite in contact with the endcap. That why you you tap it or shake it contact is re-established and the light turns on high.

It’s also in desperate need of some lube on the threads out of the box.

I don’t see any hole in the hotspot. Light/dark rings are very slight, when white-wall hunting. I don’t consider it an issue.

However, mine does have a bluish ring area surrounding the hotspot, just at the inner part of the corona.

I measure the neutral white at 4900K. So, yes, it’s definitely on the cool side. Normally, most of my neutral whites are 4000K-4500K. Sometimes even a bit warmer.

The light is definitely not regulated. Output starts off close to 900 lumens, but drops pretty linearly for 45-50 minutes, when it’s only 50% output. The low modes also drop their output proportionately.

How is that even possible? NiMH batteries have pretty flat discharge voltage curves. Even just a current limiting resistor with NiMH batteries gives pretty decent pseudo regulation.

Okay, so here’s the picture of the hotspot. It looks like I was not quite correct. It’s not actually a dim spot. It’s a blue tint spot in the center similar to the blue tint ring around it.

As to the rings in the beam, well those are harder to show, but I stand by my assertion there are numerous reasonably well defined rings in the beam, though they perhaps seem to be rings of varying tint.

Here’s the center more over exposed:

And one zoomed out more showing more of the beam which is even more overexposed:

Well, I was only eye-balling it by testing it against another light of known regulation, and adjusting its output to compare against the V4A. So, it may not have been a linear drop-off. I was primarily looking for when it was about 50% the original output, which was at about 45 or 50 minutes.

The Eneloop voltage curve under load does show a rather steep drop in the first couple of minutes (from about 1.3v to 1.2v), followed by a gentle decline down to about 1.1v over most of the run time, then a steep drop-off after that. But since the V4A load drops off over its run, that likely extends the curve quite a bit.

I’m not sure how the voltage and output is related. It’s likely that just a small dip in forward voltage across the LED results in a large drop in output. That’s maybe why it seemed to me like a steady linear drop in output over the run-time, even though the battery voltage drops more slowly than output.

Yep i also noticed kinda abit of dimming after some use but i couldnt be sure. However gradual smooth semi regulated drop might not be a bad thing as perfectly regulated light with sudden cut off might be a bigger hassle in actual use.

Hardly noticed any donuts in my light, donuts could be due to off focused reflectors. Perhaps abit of manual spacing adjustments with duck tapes around the base of the reflector to stack away or sanding the spacer flatter to stack closer might help.

I’m trying to make an output graph against runtime with my lux meter. Of course the stupid datalogging software for it only works under Windows XP. I had to go dig an old laptop out of the basement to get that all working. I have concerns about running the light on high for an extended amount of time without some cooling so I haven’t started yet. I will probably rig up a fan to blow across the light, but that will be tomorrow.

In my quick proof of concept test it dimmed about 20% in only a few minutes and the light got quite warm.

My measurements support the claim of a steady decline from 939 arbitrary units at turn on to 523 at 30 minutes, 400 at 45 minutes, and 300 at 60 minutes. So an initial sharp drop, then a steady ~100 units drop per 15 minutes.

Okay, that’s about what I noticed, too. Seems to strongly indicate a direct-driven light (with a resistor to drop the voltage to something appropriate).

I wonder how this light would perform using lithium AA primaries? They should maintain a voltage under load closer to 1.3v for a good portion of the run time. So, the light might not dim much.

I’m doing my runtime test now. I’ve got a 140mm computer case fan blowing across the light from a few inches away. I’m taking a lux reading every second. It’s stuffed in a fairly small white closet doing a pseudo bounce test of sorts. Since relative output is all that we care about that should be sufficient.

Here’s what I got. I’m going to redo it later. I may have had a battery problem. When I stopped the test one of my glitter Eneloops was at 0V while the other 3 were around 1.2V resting. They were all brand new cells straight out of the package. I put them through a conditioning cycle in a Maha MH-C808M a day ago before using them. Unfortunately, the MH-C808M doesn’t provide any capacity data. I’m recharging them in a BC-700 now so I can see if one of them is a not charging to the same capacity as the others.

The x axis is seconds.

Yes, it looks like that cell died at about the half-hour mark. Usually Eneloops are very consistent, but perhaps you found a bad one.

What did you use to create the plot?

I used Excel. Or were you asking where the data came from that went into the plot?

So, the BC-700 charged all four Eneloops fine, and the cell that dropped out first and ended with nearly 0V actually had the largest reported capacity after charging. Anyhow, I used the other 4 batteries from the same pack after I discharging and recharging them with a BC-700. I confirming they were all within +/-50mAh of each other. Here’s what I got:

As was the case last time, the x axis is seconds.