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

[WalkIntoTheLight]

Great review, I have one question about something you mentioned, though:

With the slightly larger head of the SC5, Zebralight was able to adapt their current PID thermal regulation circuit, with its temperature sensors and 384 possible sub-levels (also used on the PD62 and SC600-II). In this case however, they have kept a timed step-down for the max level (which is a lot simpler to program, apparently).

Are you saying that the SC5 uses PID to control output, if the light gets too hot? (In addition to a 3-minute timer on max.) IOW, if you didn't use a cooling fan, that your output graphs might step-down as the light gets hot (before the battery runs out)?

 

[selfbuilt]

That said, SB, are the cells you have the Japanese or Chinese made eneloops? I think the north American market is a mix of both.

That's right, it is. I have always made a point to ensure I am using the made-in-Japan ones, to guarantee consistency. It does require some hunting around though.

Are you saying that the SC5 uses PID to control output, if the light gets too hot? (In addition to a 3-minute timer on max.) IOW, if you didn't use a cooling fan, that your output graphs might step-down as the light gets hot (before the battery runs out)?

A good point, I have been meaning to test that. I know from Zebralight that they opted not to calibrate the PID for the SC5 specifically (and so relied on the simpler timed step-down from max). But I presume the PID should still work to limit heat on non-cooled runs if necessary. I will test when I get a chance and report back.

UPDATE: see testing results in post #34.

 

[Badbeams3]

Great review like always Selfbuilt! Anyone know if the light flashes when the battery get's low?

Despite the bad luck I had with the SC600 switch I had, I'm tempted to give this light a try...

 

[kreisl]

i like this light!!

 

[StarHalo]

Car headlight output with 1xAA, what an age we live in.. oo:

 

[gkbain]

One additional comment I for got to include in my previous post. Where the clip contacts the body is not dished out like the sc52 and sc32. This makes the clip on the sc5 a little harder to use and harder on the clothes. I carried the sc52 clipped to my front pocket on the inside and tried the sc5. Both are hard on the material of the paints but the sc5 especially so. I now carry an sc32 which like the sc52 has a dished out portion under the clip. One of my few complaints on a great light.

 

[fnj]

timeline's off?

Agreed; selfbuilt please double-check horizontal calibration.

 

[Swede74]

A good point, I have been meaning to test that. I know from Zebralight that they opted not to calibrate the PID for the SC5 specifically (and so relied on the simpler timed step-down from max). But I presume the PID should still work to limit heat on non-cooled runs. I will test when I get a chance and report back.

I was a bit surprised when I read that they opted not to calibrate the PID for the SC5 specifically. Last fall I received a Zebralight H32w that did not work properly, and in their response to my query, Zebralight told me this sounded like an uncalibrated light. Below is a copy of my email to Zebralight.

Do you think that the PID for the SC5 is indeed calibrated, but in a "one size fits all"-manner? If I understand correctly, in order to get maximum performance the PID has to be individually calibrated for each unit - a somewhat lengthy process - but if not calibrated at all the light will not operate at peak perfomance, at least not in my case.

If they increased the size of the head in order to make room for the PID circuit, it doesn't make sense that they would then disable it, and apparently uncalibrated lights do not work very well, so maybe the PID for the SC5 is calibrated for the average SC5?

H32W PID REGULATION

I recently purchased a Zebralight H32W, and have a question about the PID regulation of the output on H1 (446 lm). When I turn on the light (at room temperature, 20 C, powered by an AW ICR 123 750 mAh cell) output immediately starts to decline over the course of about 10 seconds. It stabilizes at an output level roughly equal to H2 (245 lm). After another 1-2.5 minutes (closer to 2.5 minutes if the light is cool, and closer to 1 minute if the light is warm) the light suddenly jumps back to an output which is significantly brighter than H2 (245 lm). If I then leave the light on, it runs for 20-25 minutes without any detectable change in output, then abruptly steps down to the medium setting. At this point the light is very hot to the touch, ~50 C according to a cooking thermometer.

Runtimes on H2, again using an AW ICR123 750 mAh cell, seem normal: ~2h @ 100 lm or ~48 min @ 245 lm.

Unfortunately the immediate drop in output when the light is turned on – H1 is essentially H2 for the first 1-2.5 minutes – and the subsequent, somewhat haphazard increase in output combined with what appears to be a lack of response to high temperature makes the H1 level practically useless.

I would also like to know if I may post a copy of your reply to this inquiry on www.candlepowerforums.com.

Sincerely,

I received a very prompt response from Zebralight

I was given permission to post their response, but since they have agreed to waive claims to privacy in their email to me rather than in the open forum, I think I would be technically violating rule #12 by posting it in full or a directly quoting it, so I will try to paraphrase:

They told me that flashlights and headlamps with the PID feature have to go through a long 'parameter' calibration process before leaving the factory, and that what I described looks like an uncalibrated light. I was also informed that calibration is done through a serial communication port in the H32w so there is no need to take the headlamp apart. I will still have to send the headlamp back to Zebralight for calibration.

They will get me a RMA tomorrow.

 

[Badbeams3]

Well I ordered one despite the bad luck I had with Zebralight in the past. But if this switch fails...I'm going to be really pissed...at myself, for not learning my lesson the first time. And of course I will put the blame squarely where it belongs, on Selfbuilt. My excuse...I needed a light to run extra Eneloop Pro's in...bought 8 for the TN4A...and have yet to need to recharge, still waiting to see that blue light turn red...so have 4 to many (a twisted way to see it perhaps, but it's my excuse and I'm sticking to it).

I decided to go with the neutral white even though it is 35 lumen less (according to Zebralight specs).

 

[markr6]

Well I ordered one despite the bad luck I had with Zebralight in the past. But if this switch fails...I'm going to be really pissed...at myself, for not learning my lesson the first time. And of course I will put the blame squarely where it belongs, on Selfbuilt. My excuse...I needed a light to run extra Eneloop Pro's in...bought 8 for the TN4A...and have yet to need to recharge, still waiting to see that blue light turn red...so have 4 to many (a twisted way to see it perhaps, but it's my excuse and I'm sticking to it).

I decided to go with the neutral white even though it is 35 lumen less (according to Zebralight specs).

I didn't learn from about 7 lessons, so...I guess it depends on what kind of beating you are willing to take Heck, I'm tempted to try this exact model again! I really don't have enough 1xAA lights.

 

[thburns]

Thanks for another great review, selfbuilt! I think I might need to pick one of these up just to start rounding out my ZebraLight collection, if anything

 

[sodakar]

Logged in for the first time in a long time just to say thanks always.

 

[selfbuilt]

Glad you are all enjoying the review.

Agreed; selfbuilt please double-check horizontal calibration.

Whoops, yup, that time-scale is off. I will update and report tomorrow, along with the non-cooled run.

 

[selfbuilt]

For those of you wondering whether the uncalibrated PID still kicks on on non-cooled run, here is a comparison:

Although there is a slight drop-off in output over time (after timed step-down), the light never seems to get hot enough on NiMH to trigger the PID step-down in my testing. Since it is hard to see the initial difference on the graph above, here is blow-up, on a 1-sec scale resolution

Basically, there is no difference. I've done a couple of re-tests, and the small jump up can occur at variable times (i.e., doesn't seem to be heat related).

So, in conclusion, it seems the SC5 never gets hot enough to trigger a PID step-down. Presumably, this is why Zebralight opted to just do a timed step-down from max - there may not be much of a need for a SC5-specific calibration, given the actual output levels.

 

[markr6]

^^ Thanks!! ^^

What would we do without selfbuilt???

 

[WalkIntoTheLight]

Interesting. I'm still left wondering whether PID is turned on at all. If you ever have time to do another test, it might be a good test to keep the light on maximum for as long as the battery holds out. That is, turn it off and back on, every 3 minutes. If it ever looks like a drop-down in brightness occurs before you would normally expect the battery to give out, that might indicate PID.

From another user's test of how long the battery can last, I think it was about 14 minutes on maximum. (Turning off and on every 3 minutes.)

 

[hatman]

Wow -- just 14 minutes on max -- can that be right?

 

[thedoc007]

Wow -- just 14 minutes on max -- can that be right?

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.

 

[Badbeams3]

Wow -- just 14 minutes on max -- can that be right?

Is that 14 from continuous resetting to max level?

 

[WarRaven]

Is that 14 from continuous resetting to max level?

Check post 36.