Zebralight SC5 (1xAA, XM-L2) Review: RUNTIMES, BEAMSHOTS, VIDEO and more!

[Badbeams3]

Check post 36.

Got it, thanks! Wonder how that compares to a SC52 running on a 14500.

 

[selfbuilt]

Yes, and selfbuilt is not the only one to find that result. Pulling six amps out of a humble AA battery is not a recipe for extended runtime.

Just to clarify, that was someone else's result, referenced by WalkIntoTheNight. But I will give it a try and see what I get.

Got it, thanks! Wonder how that compares to a SC52 running on a 14500.

Based on my SC52 14500 run (re-posted below), the light step-down somewhere between 30 and 60 secs after activation. That would be an awful lot of re-starting, which I don't plan to try.

 

[Badbeams3]

Question for the crowd. Can the hi memory be set to the 115 lumen...and double click to 500? Or if set to 115....double click goes to 200ish?

Do you have to use the 325 setting to double click and get the 500?

 

[selfbuilt]

Question for the crowd. Can the hi memory be set to the 115 lumen...and double click to 500?

Yes, that's right. H1 is always set to the 525 lm level, but H2 can set to anything you like (115, 200, or 325 lms). It remembers what you picked. So if you want the light to come in in 115, just set H2 that way and turn the light off (it will re-activate in 115). Double-click always brings you the 525lm H1 - there is no way to change that output.

 

[WalkIntoTheLight]

Just to clarify, that was someone else's result, referenced by WalkIntoTheNight. But I will give it a try and see what I get.

That would be great.

The post I mentioned about 14 minutes on maximum until the light output starts to drop dramatically, is the following post. See the last graph, after about 840 seconds, the output really drops.

http://www.candlepowerforums.com/vb...-Impressions&p=4675022&viewfull=1#post4675022


At a 6A current draw from an Eneloop, I think that's about the length of time you can expect the battery to maintain output. But, perhaps some of that is from PID kicking in to decrease output?

If selfbuilt can do a 14-minute test (keeping the light in max, and preventing the 3-minute step-down) both with and without fan cooling, that might give us a real indication of whether there's PID in this light or not.

 

[Badbeams3]

Yes, that's right. H1 is always set to the 525 lm level, but H2 can set to anything you like (115, 200, or 325 lms). It remembers what you picked. So if you want the light to come in in 115, just set H2 that way and turn the light off (it will re-activate in 115). Double-click always brings you the 525lm H1 - there is no way to change that output.

Great! That's how I think I would like to set it up. And is middle mode the same...program for 20ish lumens...double click gets you 50ish? Just looking to set it up tilted towards longer run times...

 

[selfbuilt]

Ok, I've done the repeated restarting, as shown below:

Note that I only allowed the light to step down for a few seconds before re-starting in max every 3 mins. The standard sample/plotting rate for the graphs above is once every 30 secs, so it makes for wide looking dips - but that's just an artifact of the standard graphing template I developed.

As you can see, there is no evidence of a PID being engaged at any point. The eventual step-down to lower levels occurred as normal. Note that I got just under ~25 mins on my Eneloop Pro before the light dropped to the lower levels (and again, that's with only a few seconds for each step-down).

From this, I can only assume that the standard uncalibrated PID is set to a temperature level that the SC5 never reaches, even on repeated restarts. That said, I can tell you the button area was getting quite hot near the end of all those re-starts. Using an infrared thermometer, I clocked surface temperatures at the base of the head as high as the low 70 degree C range shortly before output reached the typical H2 level.

I just checked my SC62, and surface temp on that light (uncooled) with multiple re-starts stayed in the low 60 degree C range. But you could see the effect of the PID kicking in immediately to drop output (which meant I had to keep switching for H2 and back to H1 very frequently to try and keep the temp/output up).

Up to you what you want make of the above, but I do not recommend you force repeated restarts of the H1 level on the SC5. This is clearly not what the manufacturer intended, and it is not good for a NiMH to be driven to those kinds of levels indefinitely.

EDIT: see my post #51 below for additional measurements of heat on non-restarted runs.

Great! That's how I think I would like to set it up. And is middle mode the same...program for 20ish lumens...double click gets you 50ish? Just looking to set it up tilted towards longer run times...

Yes, set H2 to 250lm, and H1 will still be 525lm on double-click.

 

[Rinspeed]

Awesome job Selfbuilt as always. Certainly going to have to pick one of these up soon. Have been carrying the SC52 every day now for almost three years and haven't had a single problem with it. I need a new light like I need a hole in my head but it's obvious Zebralight has another huge winner here.

 

[WalkIntoTheLight]

As you can see, there is no evidence of the PID being engaged at any point. The eventual step-down to lower levels occurred as normal. Note that I got just under ~25 mins on my Eneloop Pro before the light dropped to the lower levels (and again, that's with only a few seconds for each step-down).

From this, I can only assume that the standard uncalibrated PID is set to a temperature level that the SC5 never reaches, even on repeated restarts. That said, I can tell you the button area was getting quite hot near the end of all those re-starts. Using an infrared thermometer, I clocked surface temperatures at the base of the head as high as the low 70 degree C range shortly before output reached the typical H2 level.

I just checked my SC62, and surface temp on that light (uncooled) with multiple re-starts stayed in the low 60 degree C range. But you could see the effect of the PID kicking in immediately to drop output (which meant I had to keep switching for H2 and back to H1 very frequently to try and keep the temp/output up).

Excellent results, thank you. I'm concluding that there is no PID on the SC5, or at least no PID that ever activates at the temperature levels it should. 70C on the outside of the light, definitely means the LED and electronics are hotter than that.

From Cree's work on LED heat testing (the LM80 results), it appears that the LED is put under stress when the junction gets above 85C. And at 100C, the LED ages a lot faster than its expected lifetime of ~50,000 hours.

I'm not sure what temperature the LED junction reaches in your tests, but close to 100C wouldn't surprise me. Yes, probably not good to do on a regular basis, as you might only get a couple thousand hours from the LED, or burn out the flashlight electronics.

 

[markr6]

I'm sure they would have listed PID in the specs and the spreadsheet if it had that feature.

 

[selfbuilt]

Excellent results, thank you. I'm concluding that there is no PID on the SC5, or at least no PID that ever activates at the temperature levels it should.

I'm sure they would have listed PID in the specs and the spreadsheet if it had that feature.

Yes, I agree on both points. Zebralight does not advertise PID on this model. But I know from my discussion with them that all their new lights - including specifically the SC5 - come with the same standard circuit features (e.g., 384 sub-levels, temperature sensors, etc.) required for the PID thermal regulation. However, the PID parameters in each light have to be individually set (i.e., calibrated), which they have not done on the SC5, opting instead for the simpler step-down on Hi.

Apparently, this calibration for each model is a very time consuming production process. And given the output level of the SC5, I can see why would have decided to forgo it - with the timed step-down at 3mins, heat should not be a concern. I'll double-check when the temps are like without cooling or re-starts and report back.

EDIT: Just checked, and surface temps with the infrared thermometer stay below low 50 degree C range the whole time when running on max without restarts (and uncooled). That is comparable (or even a bit below) what I've seen on PID-controlled lights like the SC62 and SC600-II. Of course, that's only approximate - it's internal temp that matters, and I have no way to measure that or know how it differs to surface temp on each model.

But the point is clear - with the timed step-down on H1 here, Zebralight is able to keep the SC5 at or below the threshold of a calibrated PID on their other lights, even when uncooled. This explains why they didn't bother implementing a calibrated PID in this case.

 

[Badbeams3]

Just got mine in the mail (SC5w). First thoughts are all positive. Like the high level moon mode, even brighter than my Olight S20...so great there.

The 50 lumen mode is awesome, probably be where the light is used most often. Nice beam quality to it...plenty of energy in the spill. Spot is nice and wide, does not give me the "follow the bouncing dot" feeling I get with some lights...very nice spread of light.

Tint is perfect...no green or anything strange. Really like the neutral white tint of this sample.

High is a WOW, and considering coming from a lowly AA battery...even more so.

Have not had a chance to play with the programming, but the stock settings are really great. Probably play with it a while like it is before monkeying around with other settings. Very pleased with it I can see this will be my favorite small light.

 

[WalkIntoTheLight]

EDIT: Just checked, and surface temps with the infrared thermometer stay below low 50 degree C range the whole time when running on max without restarts (and uncooled).

What does it reach at the H2 325 lumen setting? And, if you then turn it up to H1, what does it reach by the end of the 3 minutes? Is it still below the PID levels for the SC62? (I think you mentioned that was 60C.)

 

[selfbuilt]

What does it reach at the H2 325 lumen setting? And, if you then turn it up to H1, what does it reach by the end of the 3 minutes?

I ran it for 10 mins at H2 325lm, then turned it up to H1 525lm, and measured temp when it dropped back down to 325lm 3mins later - at that point, it was still under 45 degrees C surface temp. The temp slowly rises over the course of the extended run at 325lm. By ~40 mins into the run (which is shortly before when I expect step-down due to battery exhaustion to occur), the temperature is at its highest point, and was still <53 degrees C.

I suppose if you were to jump to H1 after ~35 mins on H2, you may be able to get temps up a little bit further - but I doubt much higher than the PID level of ~60 C surface temp that I saw on the SC600-II.

 

[WalkIntoTheLight]

I ran it for 10 mins at H2 325lm, then turned it up to H1 525lm, and measured temp when it dropped back down to 325lm 3mins later - at that point, it was still under 45 degrees C surface temp. The temp slowly rises over the course of the extended run at 325lm. By ~40 mins into the run (which is shortly before when I expect step-down due to battery exhaustion to occur), the temperature is at its highest point, and was still <53 degrees C.

I suppose if you were to jump to H1 after ~35 mins on H2, you may be able to get temps up a little bit further - but I doubt much higher than the PID level of ~60 C surface temp that I saw on the SC600-II.

Thanks. I guess that makes it definitive: a 3-minute step-down is all that's needed to keep it cool enough, as long as you don't continuously set it back to maximum.

The 1-minute step-down for the SC52 on a 14500 must be overkill. It surely isn't 3x worse at dissipating heat than the SC5.

 

[GordoJones88]

Amazing review SB!

Ok, I've done the repeated restarting

Thank you so much for doing this type of runtime chart.
It really helps get a sense of what to expect on H1 when using an Eneloop Pro,
over a much longer period of time of course.

I'm Jones'in for this light now.

Now you know how I always feel.

 

[cistallus]

The manufacturer info you show says "Beacon Strobe" but doesn't detail all types/levels. You say 4 blinking modes but only mention 2 - fast and slow strobe. Does it really have a true beacon, and if so, what rate(s)?

 

[Mr Floppy]

Note that I only allowed the light to step down for a few seconds before re-starting in max every 3 mins. The standard sample/plotting rate for the graphs above is once every 30 secs, so it makes for wide looking dips - but that's just an artifact of the standard graphing template I developed.

As you can see, there is no evidence of a PID being engaged at any point. The eventual step-down to lower levels occurred as normal. Note that I got just under ~25 mins on my Eneloop Pro before the light dropped to the lower levels

I wonder what the voltage plot would look like? To me the gradual drop in ropv matches that of a NiMH discharge plot. It seems the voltage of the battery plays a significant part to the output. Would mean that the elite 2000 would maintain a higher voltage, but net effect would not be noticed

 

[WalkIntoTheLight]

I wonder what the voltage plot would look like? To me the gradual drop in ropv matches that of a NiMH discharge plot. It seems the voltage of the battery plays a significant part to the output. Would mean that the elite 2000 would maintain a higher voltage, but net effect would not be noticed

The SC52 also decreases H1 output over time, based on the Eneloop's voltage. No doubt the SC5 does that too, although it doesn't look like it drops off nearly as much as the SC52 does. The plot of the higher-voltage Energizer lithium primary looks like it performs worse than on an Eneloop, though that may be because the Energizer can't deliver the necessary current.

 

[selfbuilt]

The manufacturer info you show says "Beacon Strobe" but doesn't detail all types/levels. You say 4 blinking modes but only mention 2 - fast and slow strobe. Does it really have a true beacon, and if so, what rate(s)?

Sorry, that one "4" was a hold-over from an old review. As stated everywhere else, it are only 2 flashing modes on this light. The frequencies are given on the two oscilloscope traces.

Personally, I wouldn't consider these to be "beacon strobe" - I describe them as fast strobe and slow strobe in the review.

The plot of the higher-voltage Energizer lithium primary looks like it performs worse than on an Eneloop, though that may be because the Energizer can't deliver the necessary current.

Yes, the circuit seems to have trouble knowing what to make of the lower voltage L91 energizer lithium. Basically, with a fresh cell at least, you lose H1, and have a delay before the light will provide the highest H2A (i.e., it seems to come on in H2B instead of H1, then eventually jumps up to H2A).