# Xtar S1 Production Version (3xXM-L, 3x18650) Review: RUNTIMES, VIDEO, BEAMSHOTS+



## selfbuilt (Apr 21, 2012)

*Warning: even more pic heavy than usual! :sweat:*

_*Reviewer's Note:* This thread is a NEW review of the final shipping version of the Xtar S1, complete with new analysis, pics, comparisons, etc. The previous pre-production review - and following thread discussions - were heavily focused on a number of perceived deficiencies of the model. As these have typically been rectified, a proper full review of the shipping version of this light is presented here. Please respond to this thread with any further discussion of the final production model._

Although this review is based on the shipping production version of the S1, I will be showing some pics directly comparing the two versions, where appropriate.

So, here is the new beasty:











*Manufacturer's Specifications for the NEW Production version:*

3x CREE XM-L U2 LED
ANSI Illumination levels: SOS 2350 Lm, Strobe 2350 Lm, High 2350 Lm, Preset 15-2350 Lm 
Max Duration: 2350Lm/1hrs20Min (Tested by 3 x 18650 3100mAh battery)
Preset: 500h-1h20min 
Constant current circuit - maintains constant brightness
Smooth reflector, throws beam over 475 meters
Powered by 3x18650/3x18700 button-top battery.
Dimensions: 83mm (Head dia) x 47mm (Body dia) x 240mm (length)
888-gram weight (excluding batteries)
Made of durable aircraft-grade aluminum
Premium Type III hard-anodized anti-abrasive finish
Waterproof to IPX 8
Magnetic ring switch
Anti-roll, slip-resistant body design
Toughened glass, with anti-reflection film to ensure maximum light transmittance, and diamond film to protect from scratching.
Brightness selector. (Ways: Firstly turn magnetic ring to mode Select, secondly select brightness from 15 lumen to 2350 lumen as your request, finally turn magnetic ring to mode Preset quickly.)
Memory function. Brightness saved automatically once selected.
Brightness gradually increasing to protect eyes and circuit.
Reverse-polarity protection to prevent damage from incorrect battery insertion.
Accessories included: Flashlight, Lanyard, Pouch, Spare O-rings, Manual, Warranty card and Package.
MSRP: ~$240
Note the original specs for the pre-production version were variable, depending on the source (i.e., website or manual), and clearly inflated on some measures. To see how these new specs compare to actual testing performance of the production sample, scroll down to the end of the review.

I received the full packaging for the new production model:






The production version comes in a sturdy cardboard box with protecting cut-out foam. Inside is the light, a felt-like carrying pouch, a basic wrist lanyard, manual, warranty card, extra o-rings.









From left to right: Xtar Protected 18650; Nitecore TM11; Xtar S1 Pre-production; 4Sevens S18 Maelstrom, Olight SR92. 

All basic dimensions are given with no batteries installed:

*Xtar S1 Production*: Weight: 876.0g (est. 1028g with 3x18650 protected), Length: 240mm, Width (bezel): 83.4mm
*Xtar S1 Pre-production*: Weight: 883.4g (est. 1035g with 3x18650 protected), Length: 236mm, Width (bezel): 83.4mm
*Nitecore TM11*: Weight: 342.6g (476g with 8xCR123A), Length 135.3mm, Width (bezel): 59.5mm 
*4Sevens S18*: Weight: 700g (800g with 6xCR123A), Length: 233mm, Width (bezel) 63.0mm, (tailcap) 25.6mm
*Olight SR90*: Weight: 1.6 kg (with battery pack), Length: 335mm, Width (bezel): 97mm 
*Olight SR92*: Weight: 1.15 kg (with battery pack), Length: 271mm, Width (bezel): 98mm 

The S1 is a substantial light – overall build is quite hefty. oo: It is generally intermediate between the 4Sevens S18 and the Olight SR92. 

Overall dimensions and weight have not changed much in the production version. The production version is slightly longer, by a few millimeters – due mainly to a slightly longer head internally.

As before, construction quality seems excellent - this is a high-quality light. At first glance, the new Production version doesn't seem very different – but there are a few subtle changes.









(note: Production version is on the bottom, Pre-production is on the top)

To start, the cut-outs for the body labels are deeper now, providing more space for the writing. Label quality seems unchanged, with everything were clear and sharp.

As before, anodizing is a glossy black, and seems to be good quality. There had been a few chips on my pre-production sample, but this new production version is flawless. Reasonably aggressive knurling is present on the body, similar to before – but I found my pre-production sample to be slightly more aggressive. Along with the ridges and other build detail, grip is very good.

The tailcap area has changed from the pre-production model:














The light can tailstand stably as before. There is a built-in grip ring around the tailcap (with lanyard attachment points). There are double o-rings at the tailcap end of the battery tube. Screw threads are square cut, and seem of good quality. Tail threads are anodized for lock-out, as before. :thumbsup: 

There are three raised negative-contact points in the tailcap, which all seem linked to a common base (i.e. the three cells are clearly run in parallel). 

As you can tell from the pics, the body handle is a substantial piece of aluminum oo: – with machined areas cut-out to support 3x 18650 cells. There is a flat contact plate in the head, so you will need to use button-top or raised-top cells 18650 cells (i.e. true flat-top cells may not make contact)






One change is on the inside, where the production version now sports a sticker showing you the correct orientation of the batteries (always a good idea ).

Light has a scalloped black aluminum bezel ring. For more details on the reflector, scroll down to the beamshot section of the review.

Here are some new close-up shots of the control ring from the production version:










As before, the control ring is lightly colored, with an arrowhead marker labeled on the ring (which is still rather pale and hard to see at times). This marker lines up with mode labels clearly visible on the head, SOS > Strobe > High > O > Preset > Select (with "O" meaning Off). There are very clear detents for each mode, and I found ring action to be a bit stiffer on the production version (which is a good thing, as the pre-production could change modes a bit too easily).  I am also happy to report that it no longer turns past the available mode settings, as it did on the pre-production. :thumbsup:

There have been cosmetic changes to the ring - the circular indentations are now more pronounced, and deeper cut. Below are some images of the pre-production and production version control rings:









(note: Production version is on the bottom, Pre-production is on the top)

There is also a style change on the retaining ring right below the control switch, as shown below.









(note: Production version is on the bottom, Pre-production is on the top)

Finally, there is a slight change to how the positive contact plate looks in the head:





(note: Pre-production version is on the left, Production version is on the right)

The new positive contact column is taller on the production version, by about 3mm. 

Note too that that there are a few less threads on the body handle that screws into the head.





(note: Production version is on the left, Pre-production is on the right).

*User Interface*

The overall user interface hasn't changed on the production version, but the ramping characteristics of the Select mode has.

As before, the S1 is controlled entirely by the control ring in the head. With the tailcap fully engaged, you select your output mode by turning the ring and lining up the arrowhead indicator with the labels on the head above the ring (i.e. SOS > Strobe > High > O > Preset > Select). "O" is the Off position (actually, it's really a Stand-by mode – scroll down for details).

The output modes to the left of the Off/Stand-by mode are fairly self-explanatory (i.e., Strobe and SOS). The Preset mode refers to a memorized custom output level, selected by the user. You select the Preset mode by turning the control ring to the Select position. The light will ramp up and down in brightness, in a continuously-variable fashion, in a repeating loop. Turn back to Preset to select the level you want (i.e. this stops the ramp, and saves the current output level). The light has Preset mode memory, and will always return to this level unless you start a new Select ramp.

For a more detailed examination of the build and user interface – with a direct comparison to the pre-production model - please see my new video overview:



As always, videos were recorded in 720p, but YouTube typically defaults to 360p. Once the video is running, you can click on the configuration settings icon and select the higher 480p to 720p options. You can also run full-screen. 

*Ramp*

One of the main changes to the production version is an improved continuously-variable ramping sequence. :thumbsup:

On the pre-production S1, the ramp was very quick, with 7 secs between Min and Max outputs. But worse than that, you only had a brief fraction of a second to capture the low modes (i.e., there was no pause before it started ramp back up). I found it hard to reliably select anything below several hundred lumens on the pre-production version.

How does the new production S1 stack up?






*Note that I have presented this scale in estimated lumens, and not my usual relative output scale, to better illustrate the differences.* See my methodology section later in this review for links on how I convert to estimated lumens.

Xtar was as good as their word – they have lengthened the total ramp time to 22 secs each way, and added 1 sec pauses at 75%, 50%, 25% and Min output (in addition to Max, which always had a pause). :twothumbs:

This makes it far easier to select the low outputs. That said, the ramp time seems fairly long, and there isn't much of a relative perceptual difference at the higher lumen outputs. A brief flash at the Max, 75%, 50%, 25% and Min might have helped make it clearer to the user where they are in the process. :shrug:

*PWM/Strobe*






The S1 uses visible PWM at all levels below Max, measured at 474 Hz (consistent with the pre-production version). As with many high-output lights, this frequency is high enough to not be particularly distracting, but it is noticeable (particularly at lower output levels). 






Strobe is a fairly standard fast tactical 9.6 Hz, consistent with the pre-production sample.

SOS mode has been corrected on the production version (the pre-production was actually a repeating SO mode :laughing.

*Standby drain and Lock-out*

Due to the electronic switch design, the S1 is always drawing a small current when the light is fully connected. I measured this current as 0.66mA on one cell on the production version (which is even lower than the 0.90mA I measured on the pre-production version). Since the cells are arranged in parallel, for 3x 2600mAh cells, that would translate into 492 days (i.e. one full year and four months before they would be drained). This is quite reasonable, but I always recommend you store such lights locked-out when not in use. 

*Beamshots:*










Not much has changed here, except the production version now uses AR-coated glass. The emitters are still cool white, but are a more premium tint bin, slightly warmer than before (i.e., the pre-production had a very cool tint). According to Xtar, the original LEDs on the pre-production version were >7000K color temperature, and have now been reduced to ~5000-6000K for the production version (that's believable on my sample).

As before, each emitter was well-centered in its own reflector well (the wells overlap with each other in the center). The overall reflector is quite deep for this type of light, so expect a relatively throwy beam (with a lot of artifacts in the spill, due to the overlapping wells).

And now, what you have all been waiting for.  All lights are on their respective max battery sources (3xAW protected 18650 for the S1), about ~0.75 meter from a white wall (with the camera ~1.25 meters back from the wall). Automatic white balance on the camera, to minimize tint differences. 












































[
















Overall output has increased slightly on the production version, and tint is definitely warmer than before. The above images are all camera-adjusted for automatic white balance, but they do you give you a good relative impression.

As before, I think you can tell that throw is excellent on the S1. The spillbeam does have some very noticeable artifacts due to the overlapping reflector wells. It is also not as wide a spillbeam as the SR92 or TM11 (again, due to the relatively deeper reflector on the S1).

I haven't redone outdoor shots with the production version yet (coming soon, just waiting for a few more new lights to arrive ). For now, here are some shots of the pre-production version. These were done in the style of my earlier 100-yard round-up review. Please see that thread for a discussion of the topography (i.e. the road dips in the distance, to better show you the corona in the mid-ground). 






The S1 clearly out-throws both the Olight SR92 and Nitecore TM11. It is really no contest on the TM11, as that light is designed more for flood. Also, while the spillbeam is not as wide on the S1, it seems brighter in the mid-ground (i.e. more light is being channeled into a narrower spill width).






The S1 almost an exact match to the Crelant 7G5 for peak throw – but with a much wider hotspot and brighter spill, of course. The 7G5 is one of my best throwing single-emitter XM-L lights.

*Testing Method:* 

All my output numbers are relative for my home-made light box setup, a la Quickbeam's flashlightreviews.com method. You can directly compare all my relative output values from different reviews - i.e. an output value of "10" in one graph is the same as "10" in another. All runtimes are done under a cooling fan, except for any extended run Lo/Min modes (i.e. >12 hours) which are done without cooling.

I have devised a method for converting my lightbox relative output values (ROV) to estimated Lumens. See my How to convert Selfbuilt's Lighbox values to Lumens thread for more info. 

*Throw/Output Summary Chart:*

My summary tables are reported in a manner consistent with the ANSI FL-1 standard for flashlight testing. Effective March 2012, I have updated the Max Output ANSI FL-1 lumen estimates to represent peak output measured at 30 secs (my earlier gray tables were based on a later time point for Max output). Please see http://www.flashlightreviews.ca/FL1.htm for a discussion, and a description of all the terms used in these tables.






First thing you will notice is that Max overall output, and corresponding throw, have increased on the production version - by up to 10% in my testing. :thumbsup:

A comment here - it is very difficult to provide accurate estimates for high-output, multi-emitter lights (not least in part because the heads are often too big to fit fully inside my lightbox ). I therefore use my ceiling bounce data to help "calibrate" my lightbox, against known values for other lights. Any way you look at it, the production S1 seems to be the brightest 3x XM-L in my collection at the moment.

The lowest output level also seems to have decreased on the production version.

Reported ANSI Fl-1 specs for output and beam distance on the production version seem much more believable now.  On the previous pre-production version, Max overall output was over-stated and throw/beam distance was under-stated.

*Output/Runtime Comparison:*

One of the issues with pre-production version of the S1 was that it was driven at a level that prevented flat regulation on standard 18650 batteries (i.e., they were unable to supply sufficient power to keep the circuit at its stabilized level). The result was a pattern that looked a lot like direct-drive, where output/runtime was heavily dependent on the specific internal battery chemistry.

Let's see how the new production version compares, starting with Max output on AW 18650 2200mAh and 4GREER 3100mAh (based on the popular Panasonic NCR18650A cell):






Ok, this is much better. :thumbsup: As you can see, both relatively high and low capacity 18650 cells show stabilized flat regulation initially. The difference is how long they last before falling out of regulation near depletion.

Let's see how it compares to other lights:











As expected, the new production S1 is also able to maintain flatter stabilized regulation at its lower variable output levels.  Overall efficiency seems pretty comparable to the pre-production S1, but with greater stabilization now. Note that the S1 can go down to much lower output levels than most of the lights shown here, translating into very long estimated runtimes at the lowest levels.

*Potential Issues*

Light uses visible PWM for its lower output modes, but at a frequency (474 Hz) that is not particularly disturbing over most of the output range (i.e., I only find it particularly noticeable at the lower levels). As before, I typically prefer something at least 1-2kHz (or higher).

The continuously-variable ramp has been improved to give you the opportunity to select the truly low levels. However, overall ramp time is fairly long at 22 sec each way, and the extra pauses at 25%, 50% and 75% are probably superfluous for most users. 

Due to its "thrower" reflector configuration, there are noticeable artifacts in the periphery of the spillbeam.

Only 3.7V Li-ion cells may be used in the light (i.e., doesn't support multiple CR123A primary cells)

Completely flat-top 18650 cells will not work in the light, you need at least a small (or wide) button-top. 

Due to the electronic switch, the light has a stand-by current when fully connected. But this current is very low (<1 mA), and will not be problem for regular use (i.e. will take about a year and four months to drain three fully charged 18650 2600mAh cells).

The indicator mark on the control ring is hard to see, making it hard to tell which mode you are in by simply looking at the light. 

Light is a good size, with substantial weight (grip is good, though).

*Preliminary Observations*

As before, the S1 is an impressive light, with very good build quality and performance characteristics. The production S1 builds on the key features of the light, and adds an improved ramp, higher Max and lower Min output, better tint, and proper output stabilization on 18650 cells. :thumbsup: 

Output has received a nice bump, making this the brightest 3x XM-L light in my collection at the moment. On that point, I'm glad to see the far more realistic ANSI FL-1 specs for this light now. 

What distinguishes the S1 from most other 3x XM-L lights is the throw – this is the best throwing multi-emitter light I've seen so far. oo: It matches or out-competes all the "throwy" reflectored 1x XM-L lights I've tested for peak throw. Of course, this kind of throw in a multi-emitter setup comes as a price – expect significant artifacts in the peripheral spill (which will be narrower overall than other lights with shallower reflectors). At least the tint is a more premium cool white now. 

On the whole, I am glad to see the improvements to the continuously-variable ramp (a fairly unique feature for high-output light).  Thanks to slower ramp and pause at the Min level (the 15 lumen spec is believable), you now really do have access to the whole range. Overall ramp time is a little longer though, and there isn't much visual differentiation at the high end of outputs. 

As before, the three 18650 cells are arranged in parallel – this means you can run a lower number of cells, but with increased current draw on each one. I don't recommend you try to run most output levels on anything but the full complement of cells. 

Probably the most significant improvement for many is the proper output stabilization on 18650 cells. :twothumbs The pre-production version seemed to be circuit-stabilized only at a voltage and power level that 18650s couldn't normally achieve in operation. And since the light is PWM, that meant all the lower output levels were similarly not stabilized (i.e., PWM means the light is always driven at full power when in the On phase of the pulse). The output pattern was therefore heavily dependent on the specific battery chemistry used. I am glad to see they fixed this on the production version – the real difference between different 18650 cells is now based on their capacity at a given drive level.

As before, I am impressed to see the relatively low standby mode current (suggesting over a year before it completely drains fully charged cells). But as always, I recommend you store the light locked-out when not in use. I would personally prefer to see a higher PWM frequency, but I know that would entail a greater efficiency hit. :shrug:

Finally, there are some touches that help with the overall usability of the light (e.g., stiffer control ring, and one that only turns within the output mode choices). I am happy to see all the major issues I identified on the pre-production model have been addressed to some degrees). Although there are still a few small tweaks I would like to see, the final shipping production version of the S1 is an impressive light in the high-output/thrower space, with some fairly unique features. :wave:

----

S1 production version provided by Xtar for review.


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## Ualnosaj (Apr 21, 2012)

Awesome! Did XTAR provide their recommended Sanyo 18700 to review with it as well?


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Posted from my phone.


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## selfbuilt (Apr 21, 2012)

Ualnosaj said:


> Awesome! Did XTAR provide their recommended Sanyo 18700 to review with it as well?


No, I was just provided the light for review. I presume those would be the Xtar 2600mAh batteries (based on the popular Sanyo cell)? I have tested a single Xtar 3100mAh (based on the popular Panasonic cell), and its performance has been excellent.

FYI, for those wondering, 18650 is a bit of misnomer now ... most protected cells are at least 67mm tall, not 65mm. And many of the newer high-capacity cells are 69mm (or more). Xtar seems to be naming their cells on the basis of actual length. This is not something other makers seem to have adopted (at least, not yet).


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## Ualnosaj (Apr 21, 2012)

Yes it's the 2.6Ah ones. On a few quickie tests it appears that the 18700 discharge in a more linear fashion than the 3.1Ah Panasonics... Though the XTAR 3100 really, really give the AW of similar a run for the money, but I digress.


___________
Posted from my phone.


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## candle lamp (Apr 22, 2012)

Excellent review. Thanks for your time and sharing the useful information. Selfbuilt! :thumbsup:


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## selfbuilt (Apr 22, 2012)

Ualnosaj said:


> Yes it's the 2.6Ah ones. On a few quickie tests it appears that the 18700 discharge in a more linear fashion than the 3.1Ah Panasonics... Though the XTAR 3100 really, really give the AW of similar a run for the money, but I digress.


Yes, I notice that batteries based around the Sanyo 2600mAh cell were typically the "flattest" performers on the _pre-production_ S1. But the issue is no longer relevant on the shipping production versions - all 18650 cells show flat stabilization now, at all levels. The higher capacity cells basically just have extended runtime now (although there is likely some minor variation to the length of the fully stabilized period, depending on cell chemistry).



candle lamp said:


> Excellent review. Thanks for your time and sharing the useful information. Selfbuilt! :thumbsup:


Thanks, and very nice update to your review as well - excellent macro shots. :thumbsup:


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## selfbuilt (Apr 22, 2012)

From my pre-production review:



BWX said:


> One thing to consider though, you can still buy the pre-production version. In fact I read 'both' reviews (and more), and was thinking heavily about buying the pre-production version as it was significantly cheaper. I ended up getting production version mainly because of better tint, better regulation, and slightly brighter.. but the test version was like $40 cheaper, around $80 cheaper if not counting the discount I got on production version. Anyway....


It's a good point - for the brief period of overlapping time when both versions are available for sale, it's important to directly compare both models. But this production review has all the key information from the pre-production model as well, and is a better place to carry on discussions of direct comparisons of the two.


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## 357mag1 (Apr 23, 2012)

Thanks for the review. Good on XTAR for making the changes, it convinced me to buy one today.


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## selfbuilt (Apr 23, 2012)

357mag1 said:


> Thanks for the review. Good on XTAR for making the changes, it convinced me to buy one today.


I'm glad to see all the improvements too - especiallly the ability to select the lower outputs now. I wasn't expecting the improved stabilization/regulation, but am glad to see Xtar was able to pull it off. 

Frankly, the original circuit output/runtime performance was fine for me (i.e. you would never be able to see the slow decline in output). But if you are going to go and do all that work, it is best to ensure that your key power source is able to reach the set stabilization level (as it now does).


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## 357mag1 (Apr 24, 2012)

While I agree actual performance wouldn't appear significantly different to the eye it is important to feel like you are getting a quality product when paying that price. I couldn't quite warm up to the S1 until reading the production review. I have to give "candle lamp" some credit as well, his coverage of unprotected 18650s working in this new version helped me decide to purchase.

I can't thank guys like you and him enough for the time spent and the quality of information provided.

sbflashlights says she is on the way so maybe I can put up some comparison shots between the S1 and my TK70s.


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## selfbuilt (Apr 28, 2012)

There has been some discussion in the other S1 review threads about the production version not being regulated. 

I thought I would summarize my responses here, as readers of this review here may be curious as to what is going on.

My production sample is fully regulated on all levels, as indicated in the output/runtime graphs. However, if I try to take current measure draws with my DMM, I get unusually low readings that drop with time (i.e., instead of increasing current to maintain flat regulation).

As discussed in my earlier pre-production review thread with HKJ, this seems to be due to resistance in my DMM and/or leads. I can confirm that in my case, the light is NOT actually running at full brightness when I hook it up to a cell through my DMM. This is why lower current draws are observed - the DMM appears to be introducing resistance that is preventing sufficient power draw for regulation. 

Also, I didn't mention it in this review, but the light exhibits a "ramp-up" to full brightness over a second or two when you first turn it (on Hi, for example). Same goes for the preset mode - it (fairly quickly) ramps up from off to your set level, but it is not instantenous. This is perfectly normal for the S1, and is likely intended to be safer or more "gentle" on the batteries.


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## Ualnosaj (Apr 28, 2012)

The ramp up is definitely a characteristic of XTAR lights and supposedly by design to be gentler as you say. Whether it is really by design or a byproduct of something we'll never know 


___________
Posted from my phone.


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## Alex07 (Apr 29, 2012)

Excellent review. Thank you so much for your time and sharing the useful information.


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## madecov (Apr 29, 2012)

What, no pocket clip ! That's a deal breaker


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## BLUE LED (Apr 30, 2012)

I am glad that the production S1 is regulated. Your explaination has set my mind at ease.


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## Bela16 (Nov 24, 2014)

Hi All,
I made a runtime graph for this flashlight with dedomed LED. The results is amazing:






What is interesting, after a few minutes one led stopped to work.... after i finished the test, i try it and it work perfect, i measure the battery and it have 4.18V. 
Regarding the intensity, i got 224750 cd.... not bad
The test was made with unprotected 3400 mAh battery from Panasonic.


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## aginthelaw (Nov 4, 2015)

Bela16 said:


> Hi All,
> Regarding the intensity, i got 224750 cd.... not bad
> The test was made with unprotected 3400 mAh battery from Panasonic.




this is what made me buy one. i just got it back after dedoming and it looks marvelous enough to make me forget about the pwm. the whine however reminds me of my child/wife/boss...


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## KeepingItLight (Nov 4, 2015)

aginthelaw said:


> the whine however reminds me of my child/wife/boss...



None of whom read CPF!


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