zebralight runtime vs lumen output

[crazyk4952]

Recently, I purchased a Zebralight SC52 and a h502d. Both of these are rated to run about 50 minutes at H1 on an eneloop.

However, this has not been my experience. It seems that I get less than half of that runtime before the brightness starts to step down. I thought these were current regulated lights. I thought this meant that they would maintain their brightness until the battery was almost fully depleted.

Is my experience typical with other Zebralight owners?

 

[Badbeams3]

What type of run times are you getting off a 14500?

 

[crazyk4952]

What type of run times are you getting off a 14500?

I don't have any 14500 batteries.

 

[Badbeams3]

I see. Well using the Nitecore AA (14500) rechargeable data as a guide http://nitecore.com/productDetail.aspx?id=66 ...550 lumen off a 750 mha 14500 yields a 45 minute run time. This light has no repeated step down that I know of, but probably one timed step down to prevent overheating (to an unknown level). So I would say the Zebralight might be able to run at 280 lumen off a 750 mha 14500 for around 50 minutes.

The Zebralight info does state that the run times are based on AA rechargeables:

"Light output are ANSI out the front values. Runtime tests are done using Sanyo 2000mAh Eneloop AA batteries. Light output with 14500 batteries are the same except that the H1 is 500Lm for the first minute and then steps down to 280Lm".
http://www.zebralight.com/SC52-AA-Flashlight-Cool-White_p_100.html


But if I were to take a guess...thats a mistake. I bet the runtime test were done using their 840mha (90mha more than the cell used in the Nitecore data) 14500 cell. Easily achieving the Zebralight 50 minute claim.

As a second thought, the claim of 50 minute run time in H1 makes no claim that it will remain on that level...completely unspecified. Just total run time if started on that level, and left on...

Another guess, you will be much happier using 14500`s in this light...standard AA`s and rechargeables only in a pinch.

 

[selas]

Recently, I purchased a Zebralight SC52 and a h502d. Both of these are rated to run about 50 minutes at H1 on an eneloop.

However, this has not been my experience. It seems that I get less than half of that runtime before the brightness starts to step down. I thought these were current regulated lights. I thought this meant that they would maintain their brightness until the battery was almost fully depleted.

Is my experience typical with other Zebralight owners?

See this runtime test animation from skycamnz's excellent review of the H502c:

As you can see, the light maintains regulation well until around 40 minutes, then starts to go into mild decline. It tips over the cliff soon after 45 minutes. So on my test with the Varta 2100mAH cell, it doesn't do quite as well as ZL/s claimed run-time with an Eneloop 2000 mAH cell.

 

[crazyk4952]

I see. Well using the Nitecore AA (14500) rechargeable data as a guide http://nitecore.com/productDetail.aspx?id=66 ...550 lumen off a 750 mha 14500 yields a 45 minute run time. This light has no repeated step down that I know of, but probably one timed step down to prevent overheating (to an unknown level). So I would say the Zebralight might be able to run at 280 lumen off a 750 mha 14500 for around 50 minutes.

The Zebralight info does state that the run times are based on AA rechargeables:

"Light output are ANSI out the front values. Runtime tests are done using Sanyo 2000mAh Eneloop AA batteries. Light output with 14500 batteries are the same except that the H1 is 500Lm for the first minute and then steps down to 280Lm".
http://www.zebralight.com/SC52-AA-Flashlight-Cool-White_p_100.html


But if I were to take a guess...thats a mistake. I bet the runtime test were done using their 840mha (90mha more than the cell used in the Nitecore data) 14500 cell. Easily achieving the Zebralight 50 minute claim.

As a second thought, the claim of 50 minute run time in H1 makes no claim that it will remain on that level...completely unspecified. Just total run time if started on that level, and left on...

Another guess, you will be much happier using 14500`s in this light...standard AA`s and rechargeables only in a pinch.

Hmm. Interesting. Well if you are assuming that runtime is based off their 840 mAH 14500 cell, it seems that has about 3 watt-hours of energy. This is compared to about 2.4 watt-hours from an eneloop. So that would be about 20% more runtime, I suppose.

Anyway, maybe I misunderstand the term, 'current regulated'. All of the Nitecore and Fenix flashlights that I own will run at their specified mode for close to their rated time without stepping down. To my knowledge, these flashlights are current regulated, too.

 

[crazyk4952]

See this runtime test animation from skycamnz's excellent review of the H502c:

Thanks, that's helpful. But, I am not even getting 40 minutes at full brightness! :(

 

[Badbeams3]

The Olight S10, in Selfbuilts run time test, ran 55 minutes on a 750 mha batt...on high (320 lum) ...so for sure it can be done...

 

[reppans]

FWIW, I've tested my SC52 with a DSLR (used as an ambient light meter) and stopwatch, against some its closest competitors in the efficient/1xAA/sub-lumen category and I find that ZL.... ummm...stretches the truth a bit. ZL likes to issue stats that compete with the best 2xAAs and 1xCR123s, not only on max lumens, but also on runtime and efficiency - eg. compare the SC52 specs against the Quark AA2-XML and Eagletac D25C clicky XML - the two brightest lights Selfbuilt has tested in those respective battery classes.

I have all three XML lights in 1xAA form and find them to be about equally efficient across all modes - the ZL is slightly brighter at max, but at the expense of runtime - CLICKY. Others using light meters have produced similar results. The incredible efficiency shown in the low modes, compared 47s and ET, I find to be either outright errors, extremely poor estimations, or .... dare I say it.... misrepresentations.

From my understanding, ANSI does allow runtime specs to include lumens to drop-off as to low as 10%. Also keep in mind, no reviewer here on CPF claims to have a certified ANSI lumen scale, and each manufacturer has a different interpretation of what scale is - and from what I've seen, ZL has adopted a lumen scale ~50% more liberal than its efficient/1xAA/sub-lumen competitors - namely Foursevens, Eagletac and Thrunite, and you can triangulate this from Selfbuilt's reviews of the QAA2X, D25 clicky series, and TN Neutron 1A.

 

[crazyk4952]

Yeah, well it's really a shame. The build quality and design of these is really good.

I was really looking at the S6330, too. But, I'm not going to buy it if I can't count on the stated runtime @ each level to be at least mostly accurate.

Why did the SC52 get page after page of glowing reviews here on CPF if the runtimes are so far off from what Zebralight states?

 

[drew78]

So is the SC52 missing the mark when running on a L91 primary comapred to rechargables?

 

[selfbuilt]

And the wait is over - my SC52 review is now up. :wave:

Thanks, that's helpful. But, I am not even getting 40 minutes at full brightness! :(

As you'll see in the detailed runtimes in my review, my SC52 on eneloop starts to drop off in output around the 40 min mark.

But the Zebralight ANSI FL-1 spec of "55 mins" is actually quite accurate for my sample. The ANSI standard defines runtime as the time to 10% of peak output (with peak output identified in the period from 30 secs to 2mins). Using that metric, I have actually calculated "ANSI FL-1" runtimes for this review (they are in a table near the end). As you'll see, that same runtime that gives a drop beginning around ~40 mins actually produces a 56 min ANSI FL-1 runtime to 10%. That's not Zebralight's fault - that's what the standard measures. :shrug:

This is all part of the reason why I do not recommend people rely on the fairly arbitrary ANSI FL-1 measures for peak output and runtime, and instead look at the actual runtime curves. By focusing on just those two measures, you would really miss everything that happens in-between (which can be quite variable from one light to the next).

I discuss this a bit more on my website, in the Runtimes section of my Testing Methods page.

 

[twl]

Yeah, well it's really a shame. The build quality and design of these is really good.

I was really looking at the S6330, too. But, I'm not going to buy it if I can't count on the stated runtime @ each level to be at least mostly accurate.

Why did the SC52 get page after page of glowing reviews here on CPF if the runtimes are so far off from what Zebralight states?

Well, that would be an excellent question, wouldn't it?

I'd surmise that a lot of other people are wondering the same thing.

 

[crazyk4952]

And the wait is over - my SC52 review is now up. :wave:



As you'll see in the detailed runtimes in my review, my SC52 on eneloop starts to drop off in output around the 40 min mark.

But the Zebralight ANSI FL-1 spec of "55 mins" is actually quite accurate for my sample. The ANSI standard defines runtime as the time to 10% of peak output (with peak output identified in the period from 30 secs to 2mins). Using that metric, I have actually calculated "ANSI FL-1" runtimes for this review (they are in a table near the end). As you'll see, that same runtime that gives a drop beginning around ~40 mins actually produces a 56 min ANSI FL-1 runtime to 10%. That's not Zebralight's fault - that's what the standard measures. :shrug:

This is all part of the reason why I do not recommend people rely on the fairly arbitrary ANSI FL-1 measures for peak output and runtime, and instead look at the actual runtime curves. By focusing on just those two measures, you would really miss everything that happens in-between (which can be quite variable from one light to the next).

I discuss this a bit more on my website, in the Runtimes section of my Testing Methods page.

Awesome review (as usual)!

Based on your review, I am going to get a few 14500 batteries since it seems that those have a more consistent output.

 

[maxrep12]

Well, that would be an excellent question, wouldn't it?

I'd surmise that a lot of other people are wondering the same thing.

The excellent answer is just one post above yours, but you missed it I think:

But the Zebralight ANSI FL-1 spec of "55 mins" is actually quite accurate for my sample. The ANSI standard defines runtime as the time to 10% of peak output (with peak output identified in the period from 30 secs to 2mins). Using that metric, I have actually calculated "ANSI FL-1" runtimes for this review (they are in a table near the end). As you'll see, that same runtime that gives a drop beginning around ~40 mins actually produces a 56 min ANSI FL-1 runtime to 10%. That's not Zebralight's fault - that's what the standard measures. :shrug:

 

[twl]

The excellent answer is just one post above yours, but you missed it I think:

I did miss that, and I must have been typing my post when he put his up.

Anyway, it's meeting ANSI spec, according to Selfbuilt, which means it drops to 10% for those run times. I think there is some confusion about that, and when people read that it will run for XX minutes at a certain setting, they tend to expect it to run for XX minutes at the brightness which that level is spec'd to put out.

 

[maxrep12]

I did miss that, and I must have been typing my post when he put his up.

Anyway, it's meeting ANSI spec, according to Selfbuilt, which means it drops to 10% for those run times.

Selfbuilt:

As you can see above, the SC52 has class-leading output – for both standard AA and 14500 Li-ion. The max output on 1xAA is particularly impressive. :ooo:

It is also impressive to take a look at the run time graphs to see the how long the sc52 maintains flat regulation before it drops downward towards the 10% ANSI standard. It is not at all like the surefire eb1 that nose dives from the get go.