vadimax
Flashlight Enthusiast
The last thing that hasn’t been checked — the OP’s karma
He needs to go out to feed and stroke some kitten. They are little gods of electricity 
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I am currently testing that new Nitecore 8A low temperature battery. Some batteries will trigger the protection circuit if that draw is too high as well but this is also a known issue with high draw lights. I wonder what the rate of reduction in draw/output/whatever is for a 18650 in cold conditions (which needs also to be defined). Mostly interested as testing out that battery.
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On a side note given the numbers of batteries and chargers etc the OP has I kinda question if those are the issue but don't really know as don't own these lights.
The last thing that hasn’t been checked — the OP’s karmaHe needs to go out to feed and stroke some kitten. They are little gods of electricity
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haha...its always the batteries...
I guess I will be the first to contest that I have the same exact issue as the OP (well the first issue at least)
I own the SC600w MKIII HI and mentioned in the zebralight forum about it randomly just cutting off in H1 mode. never resolved the issue and everyone wanted to say batteries or charger.
I own the GA's that is recommended by ZL. LG's, Sony's, AW's, etc. they will all produce the same issue. I use high quality chargers/cells and I think the charger would be the least bit important to this issue. When the issue happens, the voltage isn't low enough that that should be an issue. It is obviously something in the light, electronics/circuitry. The ZL does not draw enough current to even phase an NCR18650GA
I have done a runtime test with this light on the GA, MJ1, VT6 cells and they all made it through the test. However the light will still randomly cutoff. It has a mind of it's own.
I am just here to say that the OP is not full of BS on the cutting off part and it has been a random issue for a while. I wish i had an answer for you and wish you the best of luck in getting this all figured out and/or taken care of.
I kind of wish I had the MKIV so I can comment on the max outputs. There are many variables on the output aspect but clearly you have quite a bit of experience. My guess is that in reality there is some kind of difference in output; it's just that your eyes cannot see the difference. it take quite a bit of difference in output to actually see the difference.
when we are talking over 1000lm, 1150-1400lm is nothing.
If I had the new light I could tell you the actual difference in max output, but that will not happen as i am not seeing the best news from the Mk IV's or new lights
I am currently testing that new Nitecore 8A low temperature battery. Some batteries will trigger the protection circuit if that draw is too high as well but this is also a known issue with high draw lights. I wonder what the rate of reduction in draw/output/whatever is for a 18650 in cold conditions (which needs also to be defined). Mostly interested as testing out that battery.
edit.
On a side note given the numbers of batteries and chargers etc the OP has I kinda question if those are the issue but don't really know as don't own these lights.
I agree with the output for the SC600W HI IV. I didn't have the previous model, but I have a integrating sphere and only reads 1030lm in H1 and 650lm in H2 (supposed 875lm).
I trust a lot in those results, and I also measured 3.67A current at the tail in H1 mode
I was about to return it but finally kept it because I like the tint and reading other members having the same problem, looks like all HI IV lights have the same output
...I own the mkIII and have had the same issue in different temperature environments. the only consistency is it happens when its dark and I need the light![]()
Also, I am not sure how much the cold really effects the difference while in use being that at 1000+lm, the entire light is at least near 80-90F if not much warmer. So to me, the theory of cold weather is just a myth/legend, IDK. I can understand the ability to be stored/not used in cold weather has a big effect, but not if it is a freshly charged cell used in a somewhat cold environment.
the reason why I say this is for a couple reasons, i guess. The Op as myself have used the same cells in different lights without issue. Secondly; you are aware of my runtime tests I have recently been doing. I have run these tests anywhere from freezing(30's F) to 50-60F as of late. There has been no huge difference in performance during these tests. Obviously ambient temps do have some effects but I am not sure.
Ok,
I am currently trying this freezer test on my mkIII HI.
I am currently using an LG MJ1. Freezer is around 0F
@10min: 108F at the head, 100F through body, still running
@20min: 100F at the head, still running; cycled on/off (max) for at least a min without issue
@25min: 100F at head, still running, cycled on/off for at least a min without issue
@35min: 100F at head and through body, still running, cycled on/off for around a min without issue
let it run till 40min outside of freezer, didn't cut off. approx 715lm after 40min test, 3.6v straight out of the oven, approx 2.3A current draw at this point. around 3.9A [email protected](will recheck this on fresh cell at a later time)
will try to test GA and VTC6 cells later
I'm pretty certain it's not the batteries, but rather a glitch in the electronics (regulation, boost, UI, connections, etc.)
I believe this to be the case. As I mentioned before, I had the same thing happen to my new SC600w IV HI. It would just shut off about 50% of the time when I turned it on in high. But every time I turned it back on immediately after that, it would be fine and run for however long I wanted it to. So I ruled out the batteries, dirty contacts, etc.
ZL replaced it for me and that one has been perfect. Regarding the output, it seems identical to me but I'm OK with that now. I just wanted the new UI really.
And on the note of these pulling more current that the III, I don't know. But what I do know is that I don't want ZL to start making "project" lights; lights that constantly push it to the edge just to say "look what I can do". I really don't want a light that has to have a new, freshly charged, low resistance cell, running at room temperature just to guarantee it will work. I'm not saying that's the case here, but from some of the comments, some seem to imply they're getting that finicky. I just hope ZL doesn't do that and that they continue to make solid lights...with just modest improvements if that's what it takes. I feel the IV is still a "solid" light after I took it backpacking on a deep winter trip and it worked just fine among other uses. Good so far!
I have one other suggestion-are there any other flashaholics that live near you, or anyone with at least one or two of the same lights? The reason I ask, is that if you observe someone else using and or programming the light and they see how you are doing it then perhaps something none of us has suggested may be caught. I guess another alternative is to make a video demonstrating the original problem(not the freezer cut off), then a second video demonstrating the freezer cutoff. Then you could post it here as well as send it to Zebralight. The reason I am suggesting this is because of the four Zebralights I own, I had one that I had difficulty in adjusting modes-it kept turning off. I ran into a fellow flashaholic in the Sierra Nevadas one summer and as we talked he asked to see how I was using it. As it turns out, too much or two little pressure can cause a number of issues. None of my other three lights seemed to be an issue, but after a little education by example my problem was solved. I am not saying that you, not the lights are definitively the problem, I am just suggesting you rule that out as a potential cause...
I can’t imagine the frustration you must have with the situation, and am merely trying the old “throw all the ideas at a wall and see what sticks” approach. Good Luck!
I agree with the output for the SC600W HI IV. I didn't have the previous model, but I have a integrating sphere and only reads 1030lm in H1 and 650lm in H2 (supposed 875lm).
I trust a lot in those results, and I also measured 3.67A current at the tail in H1 mode
I was about to return it but finally kept it because I like the tint and reading other members having the same problem, looks like all HI IV lights have the same output
To me, the 1568 lm is just a show-off mode
I agree. I normally don't care for those kinds of lights, but since ZL has so many other modes to choose and now fully program, I'm totally fine with it. I'll use H1 occasionally, but only for a few seconds at a time.
My head would be well and truly done in, do you think there could be a chance ZL tested your light, then sent the same one back to you. So you have actually had the same one back instead of 4 different lights. Sorry if missed it, just a thought...........other than that, it appears bad luck and some kind of glitch in the firmware.
Hope you get it sorted, i would return the light to ZL for refund. Then get another from a different source(i know its still from ZL), as then you know its a different batch(so to speak).