# Thrunite TN31 Review (1xXM-L, 3x18650): RUNTIMES, VIDEO, THROW, BEAMSHOTS and more!



## selfbuilt (May 17, 2012)

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











The TN31 is a new high-output "thrower" flashlight from Thrunite that runs on 3x18650 cells. Let's see how it compares to other recent lights in this class, including the new TN30 (a high-output 3x emitter light based on the same battery handle). 

*Manufacturer's Specifications for the TN31:*

LED: Cree XM-L U2 LED
Max 1147 lumen output using 3 * 18650 batteries: Level 1: 0.5 lm. 2000 hours; Level 2: 21 lm. 140 hours; Level 3: 146 lm. 22 hours; Level 4: 366 lm. 9 hours; Level 5: 620 lm. 5 hours; Level 6: 1147 lm. 2 hours; Standby: 65 uA; Strobe: 1147 lm. 4 hours.
Working voltage: 4V to 13V.
Max runtime: 2000 hours.
Max beam distance: 700 meters.
Peak beam intensity: 75000cd.
Impact resistant: 1.2 meters.
Waterproof to IPX-8 standard, 2M.
Dimensions: 201.70mm length, 79.00mm bezel diameter.
Weight: 452.80g without battery.
Aircraft grade aluminum body structure.
Premium type III hard anodized anti-abrasive finish.
Ultra-clear tempered glass lens with anti-reflective coating.
Momentary forward click tactical switch.
Strobe mode for tactical and emergency use.
Smooth reflector for max light output.
Highly focused beam for maximum distance.
Tactical knurling for firm grip.
Streamlined body design.
Mechanical reversed polarity protection design for battery carrier.
Intelligent highly efficient circuit board design for max performance and long run time.
Specially designed for Military, Law Enforcement, Self-defense, Hunting, Search & Rescue and Outdoor activities.
Intelligent temperature controlled light output for user safety.
MSRP: ~$220






The TN31 production version sent to me came in the full presentation case, with metal hinges and closing flaps. Inside were the light, belt pouch, wrist lanyard, manual, warranty card, and extra o-rings and spare boot cover. Note the case is larger than the TN30 that I have recently reviewed.

Also, the cut-out foam had a noticeable acrid smell when the case was first opened, likely due to some sort of outgassing that had built-up inside the sealed case. It took several days of leaving it wide open before it dropped to undetectable levels. My TN30 sample case was affected by this too, but to a much lesser extent. :shrug:













From left to right: AW Protected 18650; Thrunite TN30, TN31, Catapult V3; Xtar S1; 4Sevens S18 Maelstrom; Nitecore TM11.

All basic dimensions are given with no batteries installed:

*Thrunite TN30*: Weight: 468.2g, Length: 179mm, Width (bezel): 64.3mm, Width (tailcap): 49.0mm 
*Thrunite TN31*: Weight: 572.1g, Length: 203mm, Width (bezel): 79.0mm, Width (tailcap): 49.0mm 
*Thrunite Catapult V3*: Weight: 434.8g, Length: 254mm, Width (bezel) 58.0mm, Width (tailcap) 35.1mm.
*Crelant 7G5-V2*: Weight: 282.6g, Length: 251mm, Width (bezel): 61.4mm
*Olight SR51*: Weight: 405g, Length: 190mm, Width (bezel) 62.0mm
*Sunwayman T40CS*: Weight: 296.7g, Length 227mm, Width (bezel): 63.5mm

The TN31 is a substantial light, closer to many Search & Rescue style lights than typical 2x18650 "thrower" lights. 

Let's start with the case:














And now the light itself:














Anodizing is a glossy black, and seems to be good quality – no chips or damage on my sample. Labels were sharp and bright white against the black background. Knurling is fairly aggressive on the handle, helping with grip. Scroll down for a discussion of the control ring feel and use.

Screw threads are anodized for head lock-out. Threads are standard triangular cut, but seem of good quality.

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

Here are some close-up shots of the control ring:










There are slight indents on the control ring to help with feel. There is a label mark on the control ring that lines up with the labels on the head. The six constant output modes are not individually labeled, but there is a graded output bar pictogram over the first four levels (i.e., shows the direction to turn to raise or lower the output). There are firm detents at each level, with a slight click as you enter into each one.


















There is a metal battery carrier that holds 3x 18650 cells. The positive contact plate is slightly raised, so all types of 18650 cells should work fine (i.e., true flat-tops, wide and small button-tops). Longer cells may be a bit tight, but my protected 3100mAh cells all fit. The carrier can be inserted either orientation into the handle. Note that particularly wide cells may be a tight fit into the handle.





(from my TN30 review, but it looks the same here - the battery/body handles are the same).

The light can tailstand stably, and the tailcap cut-outs facilitate access to the switch. Switch is a forward clicky switch (i.e., press for momentary, click for locked-on). Switch feel is fairly typical, with a definite click. But there's more to it than meets the eye ... 






There is a double set of springs in the base, in addition to the spring in the head. The double-set of springs in the tail is a tip-off that something interesting is going on with the tail-switch and the battery carrier. Here is what the tail switch looks like in detail:










There is clearly a circuit along with the forward clicky switch. This is presumably to provide some sort of assist to the switch, modifying the load on it. The dual springs is how it draws power from the battery carrier, irrespective of the head. Scroll down to my Standby Drain section for more info.

*User Interface*

Turn the light off/on by the tailcap clicky – press for momentary, press and release (i.e., click) for constant on. 

Change output modes by turning the control ring in the head. Arranged from left-to-right (looking down at the light, held in traditional flashlight carry), the modes are level 1 (moonlight) > level 2 > level 3 > level 4 > level 5 > level 6 (max) > standby > tactical strobe. 

No light is produced on standby, but a miniscule current will be drawn to allow the circuit to respond to a ring turn (see below). As always, I recommend you store the light clicked-off at the tailcap, or locked-out by a head twist. 

For information on the light, including the build and user interface, 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. 

*PWM/Strobe*

There is no sign of PWM on any level – I believe the light is current-controlled. 






Strobe is an oscillating frequency strobe, switching between 6.9Hz and 14.6Hz on my sample. Each frequency lasts for about 2/3 of a sec. Here is a blow-up of each strobe frequency individually:










There is a bit of a ramp-up to the peak strobe output, but it is not something you could see in practice. Strobe is quite blazingly fast to the eye.

*Standby Drain*

The "Stand By" mode on the control ring is just that - due to the electronic ring control, the TN31 will always be drawing a small current when fully connected and the tailcap switch is clicked on.

I measured this current as 96uA. Since the cells are arranged in series, for 2600mAh 18650s that that would translate into a little over 3 years before the cells were fully drained. Note this is slightly higher the 65uA standby current listed in the manual, but that may just be natural variation (e.g., my TN30 was 114uA, in comparison). This is quite reasonable for a standby current.

There is a secondary circuit in the tailcap that has its own standby drain. You don't often see physical clicky switches in these sorts of high-powered lights, likely due to their inability to handle the typical current flows. In this case, the physical forward clicky is connected to its own circuit that presumably provides some sort of assist to the switch, modifying the load on it. 

I tried to measure the current draw on the tail switch, but my DMM's uA/mA port seems to have gone on the fritz since my earlier measures of the head standby draw were taken. While I'm waiting for a replacement, HKJ reports between 20-50 uA standby drain on the tail switch (scroll down the thread for commentary).

This means that whenever the battery carrier is loaded with cells and in contact to the tailswitch, a miniscule current will be drawn (i.e., it would take at least 6 years to drain the cells, even at its highest point). But to break this current, you would need to remove the carrier from the handle.

*Beamshots:*










The emitter was well-centered at the base of a very large and deep reflector. The reflector is smooth finished, and should provide excellent throw. And as you can tell from the reflections of the blind in my office, there is a very nice anti-glare coating on the lens.

And now, what you have all been waiting for.  All lights are on their respective max battery sources (3xAW protected 18650 for then TN30/31), 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. 





























































Output and throw on the TN31 is clearly extreme – greater than my other single-emitter "thrower" lights. Scroll down for a comparison of estimated lumens and throw.

Beam profile is pretty clean, although there were some slight irregularities in the corona around the hotspot.

For outdoor beamshots, these are 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). 
_
*Note:* Sorry, I mis-labeled the TN31 as a 3xXM-L light in the outdoor pics below.  Rest assured, the TN31 is actually a 1xXM-L light._






The TN30 (3xXM-L) produces a lot more light than the TN31 (1xXM-L), with a wider spillbeam. But the dedicated throw of the more focused TN31 is impressive. Let's see how it does against other "thrower" lights in the 1xXM-L class:






Ok, it clearly out-throws the competition, including the earlier Thrunite Catapult. oo:

Let's see how it does against a throw king, the Olight SR90:






While not quite in the same category, it is getting pretty close for both throw and output. This is a very impressive showing for a 1xXM-L, 3x18650 light. :thumbsup:

*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 Lightbox 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. Please see http://www.flashlightreviews.ca/FL1.htm for a discussion, and a description of all the terms used in these tables. Effective July 2012, I have updated all my Peak Intensity/Beam Distance measures with a NIST-certified Extech EA31 lightmeter (orange highlights).






_*UPDATE AUGUST 20, 2012*: I have revised the summary table above to reflect the results of my new NIST-calibrated lightmeter._

As the beamshots indicated, the TN31 out-throws other lights in the single XM-L class, but a pretty measurable margin. Output is also higher than the 2x18650 lights, which typically max out around ~800 lumens. The TM31 appears to be able to deliver ~1100 lumens, at least initially - the light has a slight step-down after 69 secs (see my runtimes for more info).

Lowest output is slightly lower than 0.5 lumens in my testing. In fact, here is a breakdown of the estimated lumen values for both the TN30 and TN31 in my testing:






As you can see, the reported output and throw specs from Thrunite seem remarkably consistent with my testing. I suspect Thrunite did indeed get these tested in a properly-calibrated integrating sphere. :thumbsup:

*Output/Runtime Comparison:*











Output/runtime performance was quite good for the TN31 when taking into account the 3x18650 battery source. It was certainly well in keeping with other current-controlled lights at these levels. 

You will note the TN30 typically outlasts it at lower levels, but that's because the 3xXM-L emitters are each being driven to a lower level for comparable output (i.e., emitters are more efficient at lower drive levels).

As with the TN30, the light steps down slightly after exactly 69 secs of runtime. Unlike the TN30, however, the TN31 remain perfectly stabilized throughout the remaining Max output run. Flat regulation is evident at all output levels. 

Although it doesn't show in the runtimes above, the TN31 would flash a few warning flashes shortly before hitting the built-in battery protection circuit shut-down.

One quirk – instead of shutting off when the battery protection circuit was reached, the light dropped down to a moonlight mode (similar to Level 1). :thinking: Not sure why this happened, but it was a consistent observation. And this was different from the TN30, which completely shut-off (as expected).

In terms of reported ANSI FL-1 runtimes, the Thrunite numbers seem pretty good, though perhaps slightly inflated at some levels. Remember that my runtimes are done on 2200mAh cells. On 3100mAh cells, I would expect runtimes fairly close to the reported Thrunite specs.

Here is a Hi mode runtime comparison, on 3100mAh and 2200mAh batteries:






No real surprises here - the 3100mAh cells perform better.

Oh, and those little blips near the end of the L6 run on the TN30 are from the low-battery warning system of the light.

Here is a comparison of the TN31 to typical single-emitter 2x18650 lights:






As you can see, the extra 18650 provides a lot of extra runtime. But it also allows for greater overall output on the highest level. oo:

_*UPDATE MAY 23, 2012:*_ At a user's request, I have done a comparison of no cooling and fan cooling on max output on the TN31. I even measured surface temperature on the no-cooling run. On AW 18650-2200mAh, this is what I got: 






Note the left Y-axis is estimated lumens converted from my lightbox (for the two output runs). The right y-axis is the surface temperature in degrees centigrade (celcius), measured with a probe attached to the base of the head for the no cooling run only. Hard to put those numbers in context since I don't usually measure temp, but subjectively I can tell you the light got quite hot.

As you can see, the lack of cooling caused a small drop in output over time - but nothing you could ever see visually. With fan cooling, output dropped from ~1150 estimated lumens at activation to ~1050 lumens right after timed step-down, and never dropped below ~1000 lumens. With no cooling, output dropped from ~1150 estimated lumens to ~1050 lumens as before, then gradually dropped to the ~900-950 lumen range. This resulted in marginally longe runtime.

As always, take my lumen estimates with a grain of salt - they are based on a calibration of my lightbox to ceiling bounce values of other heavy output lights of known calibrated lumens. But they do seem remarkably consistent with Thrunite specs.

Also, note that my office was quite warm for this test (i.e., resting temp for the light was 28 degrees), and no cooling was applied (although a window was open in the room). Frankly, I can't imagine a real-world scenario that would be worse than indoors with poor ventilation, as done here.

Either way, you would never be able to see any of this visually.

*Potential Issues*

Due to the electronic control ring in the head, the light has a stand-by current when in "Stand By" mode. But this current is very low (96uA), and will not be problem for regular use (i.e. will take about 3 years to drain three fully charged 18650 2600mAh cells). You can break this current by clicking the tailswitch off, or loosening the head from the body.

However, there is a second standby current due a circuit in the tail to assist the physical switch. The tail circuit draws its power directly from the battery carrier, irrespective to the state of the head (i.e., the purpose of those dual springs in the tail). The current draw is miniscule (i.e., over 6 years to fully drain the cells), but the only way to break it is to remove the battery carrier from the handle.

Only 3x 318650 Li-ion cells may be used in the light (i.e., doesn't support multiple CR123A primary cells)

Light uses a battery carrier, and very long or wide cells may be a bit tight. But all cells I tested worked in the carrier, including protected flat-top cells.

The individual levels are not specifically labeled on the head of the light, so you may need to "count" detents to figure out what level you are set to.

Light drops to a low moonlight level, similar to level 1, once the batteries reach the end of their runs. Not sure why this occurred, but it was a consistent finding.

*Preliminary Observations*

Move over Catapult, Thrunite has a new throw king – the TN31. With about twice the raw lux at 1m, that translates into ~50% more overall throw for the TN31. :bow:

The TN31 is the best throwing – and highest output – single XM-L light I've tested to date. The beam pattern is fairly smooth and even, with good spill and an incredibly bright hotspot. This is one of the largest reflectors I have ever seen. oo:

Like its sister light, the TN30, output/runtime performance was very good, with the current-control circuitry providing excellent runtimes at all levels tested. Stabilization was quite good as well, with perfectly flat regulation on all levels. :thumbsup: 

The TN30 does have a relative runtime advantage when run at comparable output levels, but that's because the triple emitters would each be driven to a lower level (and emitters are more efficient at lower currents). The beam pattern is quite different of course, with lesser throw and a lot artifacts from the overlapping beam wells on the TN30.

In terms of the interface, the control ring worked well in my testing. I particularly liked the clear and firm detents at every level. The six output levels are well spaced (and very accurate to the specs), giving you plenty of output and runtime options. I am also glad to see strobe was placed after a standby mode. A good implementation of a control ring. 

I like the use of the physical clicky switch, but its implementation is a little unusual here - there is actually a second circuit in the tailcap that seems to provide some sort of powered assist to it. The standby current draw is tiny though. 

For those looking for maximum throw and output in a single XM-L emitter, I think you've found answer for the moment.  While not quite in the same category yet as Olight SR90 on both measures, it is getting close. When you consider the max runtime is pretty comparable on those two lights – despite the TN31 having half the battery pack capacity and size – that is a pretty impressive showing. oo:

----

TN31 provided by Thrunite for review.


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## peterharvey73 (May 17, 2012)

Great review as always Selfbuilt.

The TN31 with a single XM-L U2 and a 79mm bezel diameter only has 1147 lumens OTF, yet how come it has amassed 595 meters of throw?
Has it been de-domed or something?
Or is it by a combination of boosting the OTF from 800 to 1147 lumens, plus enlargening the bezel diameter from 60 odd millimeters to 79 millimeters???
Is this XM-L U2 driven much higher than the regular Cree recommended 3 amps to yield that many lumens?

Similarly, the TN30 achieves a massive throw of 400 meters, over the Nitecore TM11 of just 286 meters.
At 64mm, the TN30's bezel diameter is hardly any bigger than the TM11 at 60mm.
So is the TN30's massive throw due to being driven hard to produce the 3000 OTF lumens output?
Though the Nitecore TN11's spill still seems to be wider?


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## MichaelW (May 17, 2012)

I am thinking 3.5-4 amps.


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## BLUE LED (May 17, 2012)

Thank you for the review. I am waiting patiently for my TN31 to arrive. I am glad that it is well regulated and throws like a champ. The long runtime on maximum is also impressive. The low low is also rather unexpected for a high output thrower 

I think the pics should state single XM-L.


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## HKJ (May 17, 2012)

A nice review as usual, but you got the switch wrong. It does not turn the power 100% off, it has some electronic assistance that needs a small amount of power.


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## selfbuilt (May 17, 2012)

peterharvey73 said:


> Or is it by a combination of boosting the OTF from 800 to 1147 lumens, plus enlargening the bezel diameter from 60 odd millimeters to 79 millimeters???
> Similarly, the TN30 achieves a massive throw of 400 meters, over the Nitecore TM11 of just 286 meters.
> At 64mm, the TN30's bezel diameter is hardly any bigger than the TM11 at 60mm.


The greater output is part of the reason for greater throw. But a lot of it is also bound to be due to the reflector. Note that it is a lot more than just the overall reflector width - depth and overall shape/design matter greatly. 

For example, the TM11 and TN30 have similar sized heads, but the reflector well geometry is completely different. The individual TN30 reflector wells are more than twice as deep (looks closer to 3x as deep), with the 3 emitters much closer together. This obviously gives good throw. Note that the TN30 reflector wells are not as deep as Xtar S1, which is an even better relative thrower. 



HKJ said:


> A nice review as usual, but you got the switch wrong. It does not turn the power 100% off, it has some electronic assistance that needs a small amount of power.


Interesting. Do you have a measure of its current draw, or a suggestion as to how I can measure it? I'm guessing it has to do with the large spring in the base making separate contact with the carrier?

FYI, when I was measuring the ring standby current in th head (96-114 uA for the two lights), I tried turning the light off at the clicky - it dropped my current reading to zero (i.e. undetectable on my DMM's uAmA port). For all intents and purposes, it looked to me like the switch completely cut the circuit.

But of course, I wasn't measuring between the tailcap and the carrier. I was suspicious of why the secondary spring was there, but couldn't get any specific reading.


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## HKJ (May 17, 2012)

selfbuilt said:


> Interesting. Do you have a measure of its current draw, or a suggestion as to how I can measure it? I'm guessing it has to do with the large spring in the base making separate contact with the carrier?



I measured 20uA to 50uA, depending on on/off status. If you open the back you can also see the electronic. I did that in my review.




selfbuilt said:


> FYI, when I was measuring the ring standby current in th head (96-114 uA for the two lights), I tried turning the light off at the clicky - it dropped my current reading to zero (i.e. undetectable on my DMM's uAmA port). For all intents and purposes, it looked to me like the switch completely cut the circuit.
> 
> But of course, I wasn't measuring between the tailcap and the carrier. I was suspicious of why the secondary spring was there, but couldn't get any specific reading.



The two springs are to supply current to the tailcap circuit, you need to measure the current from the battery to them.
When off the current to the head is zero (or at least well below the uA range).


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## selfbuilt (May 17, 2012)

HKJ said:


> I measured 20uA to 50uA, depending on on/off status. If you open the back you can also see the electronic. I did that in my review.


There was a bit of blue lock-tight on the threads, but I got it open. I see what you mean, there is clearly a circuit there. That clearly explains the presence of the second spring. I'll update the review with pics later and a revised description.

Unfortunately, my DMM's uAmA port seems to be on the fritz all of the sudden, I am not able to get any readings on any light. Not sure how that happened, but I will see about getting a replacement fuse to see if it helps. So, until I get a replacement, I will go with your estimates as to the current draw.


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## light36 (May 17, 2012)

Wow great review as always , after reading your review of the Trunite TN31 i am ordering one . Selfbuilt your reviews are always tops !!!!.


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## orbital (May 17, 2012)

+

*88.7K!!!!!!!!!

___________________________________


*


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## BMAN (May 18, 2012)

TN 31 arrived today.

http://www.candlepowerforums.com/vb...good-thrower&p=3946317&viewfull=1#post3946317


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## ergotelis (May 18, 2012)

TN31 should be giving more than 4amp to the led, more likely 4,5-5 in order to produce 1100OTF. In a copper base for sure. 
To be honest, with such a big reflector and this drive current, i was expecting higher lux numbers.
At similar sized trustfire X7/X8 reflectors,a lot of members managed with a [email protected],5amp about 90,000 lux(and me too).
At higher driving levels, some members archieved 110,000+ lux.


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## candle lamp (May 19, 2012)

Another excellent review. Eric! :thumbsup:
Thanks a lot for your efforts & time always.
It's an amazing thrower king light now.
How do feel about inserting the battery carrier into the battery tube? Is it too tight or suitable fit?


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## selfbuilt (May 20, 2012)

candle lamp said:


> How do feel about inserting the battery carrier into the battery tube? Is it too tight or suitable fit?


It was fine on my samples, as long as you are careful to make sure the batteries are all firmly installed in the carrier. Tolerances are tight, but not unreasonable for the cells i tried.


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## HIDblue (May 20, 2012)

Awesome review selfbuilt! :twothumbs Subscribed to your youtube channel as well.


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## jasonck08 (May 23, 2012)

Great review as always.

Also can someone assist in identifying the reason for the circuitry on the tail switch?

I see what appears to be a couple small N-channel mosfets, 2 resistors, and a few diods of some sort? Reverse polarity diodes perhaps?


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## HKJ (May 23, 2012)

jasonck08 said:


> Also can someone assist in identifying the reason for the circuitry on the tail switch?
> 
> I see what appears to be a couple small N-channel mosfets, 2 resistors, and a few diods of some sort? Reverse polarity diodes perhaps?



As I wrote in my review it is probably to reduce the wear on the mechanical switch. This is mostly useful in the TN30, but because the TN31 uses the same body it gets the same construction.


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## selfbuilt (May 23, 2012)

Some concern was expressed in another thread about a thermal step-down in output if no cooling was applied. I have tested this on AW 18650-2200mAh, and here's what I got: 






Note the left Y-axis is estimated lumens converted from my lightbox (for the two output runs). The right y-axis is the surface temperature in degrees centigrade (celcius), measured with a probe attached to the base of the head for the no cooling run only. Hard to put those numbers in context since I don't usually measure temp, but subjectively I can tell you the light got quite hot.

As you can see, the lack of cooling caused a small drop in output over time - but nothing you could ever see visually. 

With fan cooling, output dropped from ~1150 estimated lumens at activation to ~1050 lumens right after timed step-down, and never dropped below ~1000 lumens.

With no cooling, output dropped from ~1150 estimated lumens to ~1050 lumens as before, then gradually dropped to the ~900-950 lumen range.  This resulted in marginally longe runtime.

As always, take my lumen estimates with a grain of salt - they are based on a calibration of my lightbox to ceiling bounce values of other heavy output lights of known calibrated lumens. But they do seem remarkably consistent with Thrunite specs.

Also, note that my office was quite warm for this test (i.e., resting temp for the light was 28 degrees), and no cooling was applied (although a window was open in the room). Frankly, I can't imagine a real-world scenario that would be worse than indoors with poor ventilation, as done here.

Either way, you would never be able to see any of this visually.


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## selfbuilt (May 24, 2012)

My response to another thread on this light, about comparing lumen estimates between reviewers:

None of us have permanent access to true NIST-calibrated and maintained integrating spheres of appropriate size for all lights. And even if we did, there are still plenty of factors that can lead to spurious results. Plus, you must understand the natural variation between samples, runs, etc. Manufacturers are not required to report these variations (i.e., ANSI FL-1 just requires reporting of the average of 3 samples - no variance measures reported, and 3 is not large number to start with). Given all the adjustment errors involved, no one should infer any sort of true accuracy to the implied level of precision some people seem to like to report for their own boxes. 

Keep in mind, precision is based only on your ability to get reliable repeated measures of the same light in the same box, over and over again - it tells you nothing about how representative that one sample is, or how accurate the box is (i.e., it can only be used for relative internal comparisons).

My own lumen estimates were developed based on a comparison of my ceiling bounce readings for specific lights where the same model was measured in true integrating sphere. I make no claim to the accuracy of my numbers (as suggested by my relatively low precision in reporting - 2 sig figs with a half digit variance on the second digit). But here is a table comparing my estimates to manufacturer specs for a number of high-output lights:






The main anomaly is the SR90, but that is presumably explained by the very early testing sample I received (note the dates). I am quite confident that currently shipping SR90s meet or exceed the current ANSI FL-1 rated spec from the manufacturer, due to improved output bins on the SST-90.

The point here is that my values are directly based on the relative performance of my sample lights in my ceiling bounce room, linearly adjusted to estimated lumens by a conversion multiplication factor. It is quite possible that my values are not accurate - but the relative proportionate readings are surprisingly consistent with manufacturer specs.

Put it another way, if my TN31 were _really_ 800, or 900, or 1000 ANSI FL-1 lumens, etc., then you would have to adjust all my other lumen estimates down by the same percentage as they are based on a linear conversion of direct ceiling bounce readings (i.e., the lights are all proportionately relative to each other). Of course, it is possible that someone else has a 800 lumen TM31 - I have no idea of what normal variation is, given my single sample. But is also quite likely that their "lumen estimate" calibration differs from mine.

You have to compare any one individual's lumen values against only the other lights they have tested. You cannot compare across reviewers and samples unless you do a detail correlation analysis of all figures they report for common lights to see how much they personally differ (as I did here for my basic lightbox lumens).


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## TEEJ (May 24, 2012)

Excellent points.

I would add, as someone, in a past life who has also worked in a laboratory setting doing performance testing...ONE sample is not TYPICALLY representative of the entire product output.

This means that, exactly as Selfbuilt mentioned, ALL lights will have a RANGE of performance, just like not all Mustangs roll off the factory floor with exactly the same 1/4 mile time/speed, etc.

There are ALWAYS variations in a batch, and between batches, runs, etc.

So, generally, unless a factory's QA/QC or raw materials, etc, are really inconsistent, MOST of the product will fall into a reasonable RANGE of performance...with some outliers/salients occurring at either end of that bell curve.

So if one guy measures 1,000 lumens for light A, and 2,000 for light B....and another guy measures the same MODEL light and gets 900 for A and 1800 for B, that actually AGREES. It can mean that if YOU buy one of those lights, the output might be anywhere between those two #'s. If you KNOW they made a bin upgrade, driver changes, etc...sure, assume the LATEST reviews might have had the latest version, etc.


Personally, I trust an unbiased third party reviewer like Selfbuilt, TurboBB, HJK, etc, over a manufacturer claim.....and even if the number itself is not "accurate", it doesn't really matter, because its still proportional to the other lights' numbers from the same reviewer...and that reviewer's numbers relative to the OTHER reviewers, and so forth.

There is a system of checks and balances.

For example, NO ONE here REALLY knows what "1,000 Lumens" looks like the way a musician has perfect pitch and can hear the frequency accurately, etc. What we THINK is "1,000 Lumens" is a product of what we were TOLD was "1,000 Lumens"..and COMPARING that to what we see, etc.

So if you have a "1,000 lumen light" based on the reviews, etc...and its not able to light up things as much as you want it to...you know you want MORE THAN 1,000 L for its replacement. If SB says the light you HAVE is 1,000 L, and another light he reviewed is 2,000 L, you KNOW its about twice as bright...and will light up MORE THAN your "1,000 L" light, and so forth.

The fact that your "1,000 L light" was putting out 1,200 or 800 L doesn't matter, the fact that the "2,000 L Light" is putting out 2,200 or 1,800 L doesn't matter, because it doesn't impact your decision process...the data essentially means the same thing.




If the reviewers DID have a calibrated IS, that would be great of course, but, the LIGHTS will still vary...and they would need to be sent perhaps several lights from different batches, etc...to establish a performance curve....otherwise, they are STILL only able to say what the ONE light they were sent did....and hope its at least representative of the range a consumer might be shipped.


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## selfbuilt (Jun 13, 2012)

I have just updated the review with some discussion on peak intensity measuring.

I realize that people are very sensitive to minor differences in raw lux @1m numbers for these thrower lights. But as with lightboxes, you can only really compare throw values to other lights tested with the same meter, under common conditions (i.e., calibrations vary, sometimes widely). Up until now, the light meter used for beam intensity/distance measures in all my summary tables has been the budget Cer CT1330B (which is generally believed around here to commonly have lower numbers than some others lux meters). I recently picked up the slightly more expensive budget-model V&A VA8050, which gives me higher lux readings.

As I have no idea which of these lux meters is closer to the "true" reading, I have recently ordered a proper NIST-calibrated and certified Extech meter. This should resolve the matter, and I will update this review with new throw measures once it arrives. In the meantime, I have re-tested the TN31 on both meters, and get 93,000 lux @1m (610m beam distance) on my standard Cer and and 117,000 lux @1m (684m beam distance) on the new V&A meter. 

Note my Cer lux readings have gone up slightly from what was orginally posted up above in the table. That's likely because I didn't quite manage to find the absolute peak intensity in my earlier measure (ANSI FL-1 beam tests involve moving the hotspot around the light meter sensor manually, and recording the absolute maximum obtained). As such, there can be some variation on repeated measures.

Anyway, I will be able to provide more accurate calibrated intensity/distance values once my next NIST-certified lux meter arrives. :wave:


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## brightnorm (Jun 13, 2012)

selfbuilt said:


> For those looking for maximum throw and output in a single XM-L emitter, I think you've found answer *for the moment.*



Selfbuilt,

Your excellent review reminds us of the inevitable.

Brightnorm


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## Mar (Jun 14, 2012)

This is excellent news selfbuilt, I have a 31 and it's a good thrower. I plan on climbing a tall hill around here a photograph some shots to a reflective tape approximatey 1000 meters away.

Looking forward to hear more once your are fully set up with the new toys.


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## indenial (Jun 15, 2012)

Your reviews are brilliant and exhaustive! I just hope you're compensated for them! Thank you!


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## selfbuilt (Jun 15, 2012)

indenial said:


> Your reviews are brilliant and exhaustive!


Certainly exhausting! :laughing: I will be away most the last week of June and first week July, so I am rushing to get a whole bunch of reviews out by the end of next week. Seem to have a lot of throwers on hand ... but the TN31 remains a real stand-out for its size.

By the way, here's an extra outdoor shot from my recent Olight SR95UT review:







I will update this thread with additional comparison shots once the next couple of reviews come out ...



> I just hope you're compensated for them! Thank you!


Only by the respect of my peeps here.  I don't accept any form of compensation for the reviews (other than keeping the light once testing is complete), as that could potentially bias my conclusions. That's why donations to my battery fund from regular members is always greatly appreciated. :wave:

I actually try to maintain a fairly discrete arms-length arrangement with all the dealers and manufacturers. For example, I typically leave it up to them to make contact and request a given light be reviewed (i.e., I don't solict reviews, again for the potential for bias). The exception is when I've received a number of requests from members to review a certain model, and have passed that along for their consideration. 

That said, there is a definite selection bias in what I choose to review - my time is limited, so I only agree to review what looks interesting to me. I typically wind up turning down almost as many requests as I accept. :sweat:


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## TEEJ (Jun 15, 2012)

Mar said:


> This is excellent news selfbuilt, I have a 31 and it's a good thrower. I plan on climbing a tall hill around here a photograph some shots to a reflective tape approximatey 1000 meters away.
> 
> Looking forward to hear more once your are fully set up with the new toys.



Reflective tape is a poor target choice to test throw, as it is too easily seen to be representative. I can light up tape and reflectors at distances that are simply dark except for the reflected light.

For example, a ZL SC600 has a useful range of approximately 50 yards of throw....past that, its too dark to make things out in practice. I can light up reflectorized materials over 800 meters away with it.

If I then said its throw was 800 meters, it would be very misleading. Even a white or shiny target surface can be misleading, for similar reasons.

At 1,000 meters, even in daylight, it can be hard to make out details...and in dim light, its a LOT harder. 

It might be pragmatic to simply see what you can SEE well enough to feel that if USING the light to see with, that you'd find what you were looking for....and then use Google earth, etc, to see what the result was.


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## indenial (Jun 15, 2012)

Those latest beamshots comparing the TN31 to the Olights convince me that its form factor, performance and lower price make it an amazing value and - not to mention quite a design feat!


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## VIET PRIDE BULLIES (Jun 16, 2012)

Nice review, the comparison shot are nice compare to big lights. It makes this light good value for the money


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## brightnorm (Jun 19, 2012)

I ordered the TN31 based on this excellent review. I think the side-by-side battery configuration will become more popular over time as more people have the opportunity to experience its advantages.

Brightnorm


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## selfbuilt (Jun 19, 2012)

indenial said:


> Those latest beamshots comparing the TN31 to the Olights convince me that its form factor, performance and lower price make it an amazing value and - not to mention quite a design feat!





VIET PRIDE BULLIES said:


> Nice review, the comparison shot are nice compare to big lights. It makes this light good value for the money





brightnorm said:


> I ordered the TN31 based on this excellent review. I think the side-by-side battery configuration will become more popular over time as more people have the opportunity to experience its advantages.


Yes, the TN31 is quite a stand-out for the size. I was amazed to see how close it throws to my stock SR90. oo:

I tend to trust the absolute numbers of the V&A lux meter a little more. Unfortunately my NIST-calibrated Extech light meter had to be re-ordered (Extech accidentally forwarded a thermocoupler datalogger to NIST on my behalf instead).  They are rushing the correct replacement, but even with UPS shipping, it will likely still be a couple of weeks.

For those sensitive to price, I hope to have my Crelant 7G9 review up by the end of the week. We'll see ...


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## Fitz (Jun 19, 2012)

Very interested to see how it does against the 7G9, looking forward to some comparison shots. Sent a little donation for your battery fund, thanks for the great reviews!


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## selfbuilt (Jun 19, 2012)

Fitz said:


> Very interested to see how it does against the 7G9, looking forward to some comparison shots. Sent a little donation for your battery fund, thanks for the great reviews!


Thanks for the donation, much appreciated.


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## brightnorm (Jun 21, 2012)

Just a nitpick, but I noticed in the outdoor comparison with the OLight SR 90, the TN31 is identified as a 3xXML light.

Brightnorm


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## selfbuilt (Jun 21, 2012)

brightnorm said:


> Just a nitpick, but I noticed in the outdoor comparison with the OLight SR 90, the TN31 is identified as a 3xXML light.


Thanks, good catch. I've just added an explanatory note in the text correcting that. I don't have time to re-label the images right now.


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## BLUE LED (Jun 21, 2012)

brightnorm said:


> Just a nitpick, but I noticed in the outdoor comparison with the OLight SR 90, the TN31 is identified as a 3xXML light.
> 
> Brightnorm



I noticed this also on post #4


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## brightnorm (Jun 21, 2012)

selfbuilt said:


> *...*Although it doesn't show in the runtimes above, the TN31 would flash a few warning flashes shortly before hitting the built-in battery protection circuit shut-down.
> 
> One quirk – instead of shutting off when the battery protection circuit was reached, the light dropped down to a moonlight mode (similar to Level 1). :thinking: Not sure why this happened, but it was a consistent observation. And this was different from the TN30, which completely shut-off (as expected)...
> 
> TN31 provided by Thrunite for review.



These are terrific "quirks"! Warning flashes and moonlight mode instead of the sudden death we are all too familiar with in many well-regulated liON lights. Bring on more quirks!

Brightnorm


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## brightnorm (Jun 23, 2012)

I received my TN31 today and just tried it out. It is truly a "throw-monster", especially monstrous considering its relatively modest size. Since its body diameter is just a few millimeters less than the TM11 I am surprised they didn't make it a 4x18650 light .

BN


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## weqr (Jul 6, 2012)

Any of you guys have a yellow tint around the hotspot on your TN31? Mine has this and its quite noticeable. Reminds me of the same that I have with my Fenix TK35.


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## BLUE LED (Jul 6, 2012)

I have no problems with my TN31. The tint around the hotspot is slightly warmer.


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## Alex1234 (Jul 6, 2012)

I just recived my tn31 and throws really good when i recived my light in the mail and took it out to hold it it was really hot because its 100 degrees today outside. I hope that dident do any harm to my light. I campared it to my fatmax and the hot spot is slightly brighter but a tad bigger. I actually thought it was going to be a lot brighter then it. Whats everyones opionin on ultrafire 18650 batteries?


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## selfbuilt (Jul 6, 2012)

Alex1234 said:


> when i recived my light in the mail and took it out to hold it it was really hot because its 100 degrees today outside. I hope that dident do any harm to my light.


Don't worry, it gets a lot hotter inside the light during use - outdoor temperatures shouldn't be an issue.



> Whats everyones opionin on ultrafire 18650 batteries?


You might want to take that over to the battery sub-forum here, but my opinion is not high. There is too much variability between suppliers to know what you are actually getting (ultrafire isn't really a defined brand, more a loose standard that is heavily duplicated). There have been plenty of reports of used/pulled laptop batteries finding themselves under ultrafire-branded wrappers. I would recommend sticking with a quality brand name - again, the batteries subforum is a good place to look.


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## Alex1234 (Jul 7, 2012)

I had a chance to compare the throw to my deree ez900 aspheric at a tree 500 feet away and they were pretty much the same. its kinda hard to tell because its kinda werid comparing a low luman ashperic to a 1100 luman throw monster. the low output of the aspheric just makes it not as impressive at very long distances like the tn31. overall the tn31 is awesome and that huge deep reflector is perfect.


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## HighlanderNorth (Jul 22, 2012)

A few questions:

1. I assume the manufacturers send you the vast majority of these lights, so do you get to keep these lights after you do the reviews? You always seem to have LOTS of lights lined up for comparison purposes! If the reviewer gets to keep the lights after the review is finished, then I'll volunteer to do these for a while, and even though I dont have any of the equipment to do any of the measurements with, and I dont even understand some of it, I guarantee that my reviews will be 5-10% as thorough as yours are, and they will contain 'some' accuracy mixed with lots of subjective opinion!

2. Why is the Olight SR-90 now being listed at between 1450-1700 lumens, when it has been advertised at 2200L for a long time now. Is it really losing that much brightness through the reflector and lens?

3. Of these smaller, shorter 3 or 4 18650 lights with 1 or 3 LED's, which would you personally prefer between them? For instance, the TN30, TN31, TM11, SWM T60CS, etc? I am currently trying to decide between these lights, and I've never seen any of them in person.

4. Do you generally prefer a floody or throwy(is that a word?) beam? Or do you like a happy medium between flood and throw?


Anyway, good review again....


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## selfbuilt (Jul 22, 2012)

HighlanderNorth said:


> 2. Why is the Olight SR-90 now being listed at between 1450-1700 lumens, when it has been advertised at 2200L for a long time now. Is it really losing that much brightness through the reflector and lens?


ANSI FL-1 standard was not in commonly in use when the SR90 launched, so manufacturers typically reported specs however they felt like it. The "2200 lumen" spec referred to theoretical maximum output of the emitter. Olight has subsequently adopted ANSI FL-1, and refers to the light as "1750 lumens" (which seems believable for recent ones).

Part of the confusion comes from the earlier batches of lights (like mine) which underperformed relative to the newer "true" 1750 lumen ANSI FL1 lights. There seems to be a bunch that were closer to the 1400 lumen level. This likely reflects the wide variability in a given Luminus output bin (i.e. they bin in ~20% wide increments), and a possible bin upgrade over time.



> 3. Of these smaller, shorter 3 or 4 18650 lights with 1 or 3 LED's, which would you personally prefer between them? ... 4. Do you generally prefer a floody or throwy(is that a word?) beam? Or do you like a happy medium between flood and throw?


Hard to answer - it really depends on the situation. In general terms, I tend to like relatively throwy lights with a diffuser option. That way you always have a choice.

But for all these 3x, 4x 18650 lights, the output and throw exceeds any specific needs I have. I typically recommend people choose on the basis of preferred interface and build.


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## veedo (Aug 1, 2012)

maybe i missed it somewhere, but does anyone know how much current the led is pulling on turbo?


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## selfbuilt (Aug 1, 2012)

veedo said:


> maybe i missed it somewhere, but does anyone know how much current the led is pulling on turbo?


You didn't miss it - for that kind of measure, you need to use a bench-top power supply (which I don't have) and directly measure at the head. Check out HKJ's excellent review of this light for those measures.


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## bigchelis (Aug 20, 2012)

This Thrunite TN31 is really impressive.

I got to test a sample and side by side with SR90 domeless which net me 200K lux the sample we had gave us 115K lux. The Stanley XM-L fatmax with 3A current to LED net 77K lux.

Awesome overall brightness and really great thrower.

bigC


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## selfbuilt (Aug 20, 2012)

bigchelis said:


> This Thrunite TN31 is really impressive. ... the sample we had gave us 115K lux.


That result is quite believable. Beginning last month, I've started providing new summary tables that reflect a new measuring protocol - all my Peak Intensity/Beam Distance measures are now done with a NIST-certified Extech EA31 lightmeter. See that thread for more info, but you will able to tell the new tables because they have orange highlights for the new throw measures.

Here is how my TN31 compares to the competition:







As you can see, a very comparable ~113K lux @1m equivalent. :thumbsup:

I'm not planning to go back and revise all the old reviews (well, except this one ), but the new numbers will show up all in all new reviews going forward.


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## DanM (Aug 20, 2012)

Thank you Selfbuilt I love your reviews and your charts. 

Has anyone tested the Thrunite NT31's throw at any of the reduced outputs.
For example would the NT31 at 620 lumens be close in throw to the lets say the Catapult V3 or the Sunwayman T40CS. 
The reason I ask is that as lumens rise with these new lights many can only maintain there high output for a shot time
before dropping down a level.


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## Landshark99 (Aug 29, 2012)

Thanks for the review, ordered a TN31 yesterday, should be here tomorrow


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## selfbuilt (Aug 29, 2012)

DanM said:


> Has anyone tested the Thrunite NT31's throw at any of the reduced outputs.
> For example would the NT31 at 620 lumens be close in throw to the lets say the Catapult V3 or the Sunwayman T40CS.


Sorry for missing this earlier. I just checked, I measured nearly 76,000 lux @1m equivalent with the NIST-meter on the ~620 lumen L5 of the TN31. So that makes it a better thrower than the Catapult or T40CS for roughly similar output.


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## rustlerdudr987 (Aug 29, 2012)

For anyone looking to buy the TN31 there is a new modded TN31 for Saabluster it has a lux rating of *240* lux!
http://www.onestopthrowshop.com/ThruNite-TN31-TN31.htm


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## ma_sha1 (Aug 29, 2012)

Wow, 

the new NIST numbers match up my Extech EA30 meter perfectly. MY SR51 does 51K lux, always wondered why your old numbers of SR51 was so low, in the low 40K lux range. I can consider my EA30 meter indirectly NIST certified ? 

I have a SR95 UT coming in, can't wait to measure it. Almost 200K lux with a big SBT die, yeah!


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## DON KIDIK (Sep 1, 2012)

Good evening,i just wanted to say what a kewl review as usual and an awsome product.

Mostly also to say thanks for the information and attention to detail.I have read quite few of your reviews now and sorta feel like we are mates:wave:almost.Its great to have this forum as refrence,Very welldone sir.



I have a TN31 on order,Cant wait now .


Have a goodn all

DON...


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## DENGOH (Nov 7, 2012)

Is it my TN31 having issue as I found problems below seems like no one mention about it:
1.The hottest location is on the magnetic rotary switch. By looking at it, the LED is indeed sitting on the same level on the rotary switch. But then after using the light for long hours, the battery tube get quite warm. If I take out the battery at that time, the batteries are quite hot. Temperature on the heat sink on the head seems to be not doing good job as they are much cooler.

2.The rotary switch has some play to it, it is not purely rotating when touching on it and rotate, seems to be a little bigger than ideal gaps between the rotary and body.

This is very good flashlight. Just want to make sure is this something Thrunite should improve for their future flashlight. Or it is isolated mechanical problem or my batteries problems.


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## xed888 (Nov 9, 2012)

*Re: Thrunite*

There's a slight play in my TN30 so it's normal


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## rednek (Nov 10, 2012)

I just revived my TN31 that i ordered a week ago. it looks like a real cool light the only problem is i cant find anyone locally that has 18650 batteries?

Any suggestions on were to order from? :shrug:


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## Yourfun2 (Nov 11, 2012)

I bought mine from Goinggear.com, Eagletac 3100 mah.


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## biglights (Nov 11, 2012)

Yourfun2 said:


> I bought mine from Goinggear.com, Eagletac 3100 mah.



That is what I am using also, don't forget the discount code! I have never seen 18650 batteries in stores.


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## rednek (Nov 12, 2012)

Of all the places I found 4 18650's at a yard-sale. Not the best place to pick up batteries but they will get me thru till I get some good ones.


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## hivoltage (Nov 17, 2012)

How does this compare to the Jetbeam RRT-3? Looking for something to outperform it. Thanks


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## DENGOH (Nov 17, 2012)

*Re: Thrunite*



xed888 said:


> There's a slight play in my TN30 so it's normal


I just got my TN30 and it has slight play either. But TN31 has slightly more play. I think it is normal for Thrunite. Hope that it is not because they didn't put some o-ring under it.


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## TEEJ (Nov 17, 2012)

hivoltage said:


> How does this compare to the Jetbeam RRT-3? Looking for something to outperform it. Thanks



Apples and oranges...the RRT-3 has a nice floody beam with throw, the TN31 is a pretty pure thrower.

The TN31 will out throw the RRT-3, but light up a smaller area at a time.

The TN30 might be a better replacement than the TN31 would be for example, for your RRT-3 if you want to see more at a time.

So it comes down to what you mean by "outperform". The SR95UT out throws the TN31 for example, by a good margin...so if you are looking for a lot of throw, the SR95UT or Saabluster's modified TN31 for example, will be strong contenders if its range that you need.

The RRT-3 is not a thrower per se...I love mine, but, I love floody beams.


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## peterharvey73 (Nov 19, 2012)

hivoltage said:


> How does this compare to the Jetbeam RRT-3? Looking for something to outperform it. Thanks



Your RRT-3 Triple XM-L has a "flood-throw" type beam.

Thus, the TN31's sibling - the TN30 Triple XM-L may outperform your RRT-3 Triple XM-L?
Else a huge Xtar Triple XM-L; forgot the model number - S1?
Else a humungus Olight SR92 6x18650 powered Triple XM-L?

On the small side, perhaps the new Nitecore TM15 Triple XM-L flood-throw-plus with 431 meters of throw, and 2450 lumens??? Though the TM15 may only just out-throw the RRT-3 Triple XM-L.
See Selfbuilt's review: http://www.candlepowerforums.com/vb/showthread.php?347524

Meanwhile, the Sunwayman T60S Triple XM-L is pretty floody at 369 meters of throw.
You already know the TM11 is tiniest and floodiest at just 332 meters of throw...


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## TEEJ (Dec 10, 2012)

Has anyone figured out why Thrunite rates the TN31 at only 75k cd BUT WITH A THROW of 700 meters?

All the third party tests put the throw in the 600+ M range, and ~ 115k-ish cd ranges.

?


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## hahoo (Dec 10, 2012)

TEEJ said:


> Has anyone figured out why Thrunite rates the TN31 at only 75k cd BUT WITH A THROW of 700 meters?
> 
> All the third party tests put the throw in the 600+ M range, and ~ 115k-ish cd ranges.
> 
> ?




ive wondered that since day 1 also teej...
just the opposite, as most manufactures would of changed it the very minute anybody with credentials, would of came up with higher numbers, like selfbuilt...


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## TEEJ (Dec 10, 2012)

hahoo said:


> ive wondered that since day 1 also teej...
> just the opposite, as most manufactures would of changed it the very minute anybody with credentials, would of came up with higher numbers, like selfbuilt...



Ironically, I could see NOT changing it due to SB's review, as they are (Supposedly) using ANSI lumens. That means an ANSI test...not a bounce test and a calculator would be in their ad. WE TRUST the bounce test/SB of course, but I can't see them going to court with SB over an ANSI approved lab's results, etc.

On the OTHER hand...they claim 700 M throw...which IS typically CALCULATED from the cd number.

BOTH numbers can't be correct, and, it seems that their cd # is the suspect one.

Essentially, a REAL cd measurement means knowing the PRECISE beam convergence pattern/distance so as to know at PRECISELY what distance to take the lux reading at...which THEN gets back calculated to the lux at 1 M or cd #....and which THEN gets extrapolated out to get the light's max range to 0.25 lux.



This means that an "At Home Test" is almost guaranteed to show fewer meters of max range for a strong thrower....than an ANSI test would. Its just too hard for a casual tester to spend the time required by trial and error to find that max beam convergence point, etc. Most will test at least further out than a meter...maybe 10 m, etc...but it might not be the OPTIMUM point to measure at...just better than at 1 m, etc.

So with SB's methodology being reasonably good about agreement with factory specs and other reviewer's #'s, etc...while his throw #'s esp for really strong throwers would be expected to be shy of OEM/ANSI specs...his cd readings should not be much HIGHER.

As the OEM 75k cd is a LOT lower than projected...but the OEM 700 M is in the projected ranges, I think the OEM effed up on their cd label.


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## ggroyal1117 (Dec 24, 2012)

Thanks for posting the review. I purchased the TN31 and I am very satisfied with it.


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## gilbert47830b (Feb 26, 2013)

ggroyal1117 said:


> Thanks for posting the review. I purchased the TN31 and I am very satisfied with it.


---------------------------------------------------------------------------------------------------
Hi, for those owned TN31, any one facing difficult switch on problem, need to hit the flashlight to get it on?
Thanks


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## selfbuilt (Feb 26, 2013)

gilbert47830b said:


> Hi, for those owned TN31, any one facing difficult switch on problem, need to hit the flashlight to get it on?


That would not be good - no problem on either my TN30 or TN31. Sounds like you are having a connection problem - I would clearn all contact surfaces and make sure all screws/threads are securely tightened. If you are unable to resolve the issue with this kind of preventive maintenance, I'd contact your dealer for assistance.

Oh, and :welcome:


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## clspruiell (Feb 26, 2013)

Got my TN31 last week in the mail. This thing is INCREDIBLE! Took it out to a field and had to hold it away from my body so I wasnt looking directly down the beam. It was exposing too much moisture / trash in the air. I thought about the Fenix TK75 but I felt like the spill was too much on it and I wanted a thrower with a defined beam. Plus, this light has plenty of spill.


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## RemcoM (Mar 13, 2013)

selfbuilt said:


> That would not be good - no problem on either my TN30 or TN31. Sounds like you are having a connection problem - I would clearn all contact surfaces and make sure all screws/threads are securely tightened. If you are unable to resolve the issue with this kind of preventive maintenance, I'd contact your dealer for assistance.
> 
> Oh, and :welcome:



Hi,

1 The manufacterer says only 75000 cd beam peak intensity, but 700 metres beam distance is more , over 110 000 cd.

I not understand this. Can you explain this?

2 What if you put the Tn31 on your bicycle, with turbo mode on, and you shine the lamp straight forwards into the eyes of the oncomming traffic?

3 There is another TN31, and more lumens, and more beam distance, do you know about that? Why you not have the most powerfull one?

4 How bright does the 0,5 lumens ultra low mode on yout TN31 looks to you?

Remco


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## TEEJ (Mar 13, 2013)

RemcoM said:


> Hi,
> 
> 1 The manufacterer says only 75000 cd beam peak intensity, but 700 metres beam distance is more , over 110 000 cd.
> 
> ...





1) The cd is a measure of how well the light can throw/reach long distances. There is a formula that you can use to calculate the throw if you know the cd or the cd if you know the range it can throw, etc. The TESTS of the light indicate that it throws a LOT further than the cd rating would indicate. Doing the math, the cd rating appears to be wrong, and, too low. The ABOVE math calculates that to the get the throw it can be seen to, its cd would be closer to 110,000 cd....and not the 75,000 cd its rated for.

2) If you shine almost any fairly bright flashlight at oncoming traffic you will blind oncoming drivers, just like if you had your high beams on in a car, etc...but if you aim it down ENOUGH, you can avoid blinding people if the beam is lower than their eyes, etc. As a flashlight beam is essentially round, there is no "upper cut-off" as with a real automotive beam...and those facing it are very vulnerable to you causing too much glare. 

The beam type is not ideal for a bike light, a its optimized for long range illumination, and seeing 100's of meters ahead is typically not that useful on a bike...especially when a WIDER BEAM would work better for the closer ranges you see on a bike ride. The TN30 for example would be a better bike light than the TN31, albeit the glare issue for oncoming drivers would still be problematic. Of course, on a bike, you are supposed to be with traffic not facing it...so, if on a bike path off the shoulder, etc...at least the oncoming traffic will be further away off center, etc.

3) The other TN31's came out after the review..and, one of them is a modified version of this one....and its ~ 3x the $. The TN31mb is a monster thrower, in a different league altogether.

4) It looks like a dim circle of light, about as bright as the ground would be if lit by a candle on a table above it.

- Hope that helps!


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## selfbuilt (Mar 13, 2013)

RemcoM said:


> 1 The manufacterer says only 75000 cd beam peak intensity, but 700 metres beam distance is more , over 110 000 cd.I not understand this. Can you explain this?


Their numbers are not consistent with ANSI FL-1 standard. I would recommend you rely on my actual testing results.



> 2 What if you put the Tn31 on your bicycle, with turbo mode on, and you shine the lamp straight forwards into the eyes of the oncomming traffic?


Frankly, the TN31 is throwier than I would want for a bicycle, but I would recommend you angle it downward to so as not to blind oncoming traffic (same is true for any light).



> 3 There is another TN31, and more lumens, and more beam distance, do you know about that? Why you not have the most powerfull one?


Because this review is 10 months old ... 

Thrunite has indicated they have some new lights they want me to review, but I'm not sure which models yet.



> 4 How bright does the 0,5 lumens ultra low mode on yout TN31 looks to you?


It's pretty dim.


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## TEEJ (Mar 13, 2013)

LOL


Its like an echo.


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## selfbuilt (Mar 13, 2013)

TEEJ said:


> LOL
> Its like an echo.


I guess I type slower than you do. :laughing:


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## BeastFlashlight (Mar 16, 2013)

selfbuilt said:


> Thrunite has indicated they have some new lights they want me to review, but I'm not sure which models yet.



Oh really, from what I gather in these forums Thrunite is far from a spectacular brand but they hit a home run with the TN31 (Then improved it to XM-L2). They're OK, but not great. So the fact that they're coming out with new stuff doesn't tempt me to hold off on the TN31 XM-L2, that may be their Mona Lisa (I could be wrong). Heard a lot of flickering complaints about TN30


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## tatasal (Mar 16, 2013)

There are more flickering complaints on the TN31 (maybe because a lot more people bought it)


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## BeastFlashlight (Mar 16, 2013)

Damn didn't know that. I am now thinking of which light would be a great middle ground between the beam angle of TK75 and TN31mb (I'm building an arsenal for nature vacations) I was thinking TN31 XM-L2 would be perfect but i didn't know it too had flicker complaints. Somewhere somebody had a post that said the TN30/TN31 design was better suited for the lower lumens of TN31. I couldn't even guess at the technical reasons why that would be true


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## chipdouglas (Mar 17, 2013)

tatasal said:


> There are more flickering complaints on the TN31 (maybe because a lot more people bought it)



I was just about to pull the trigger on a TN30, but I'm going to wait until I've read some more about this issue. Too bad.


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## BeastFlashlight (Mar 17, 2013)

chipdouglas said:


> I was just about to pull the trigger on a TN30, but I'm going to wait until I've read some more about this issue. Too bad.



In your research did u also consider Nitecore TM26? Just wondering because for awhile I couldn't decide between TM26 and TN30 XM-L2


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## tatasal (Mar 17, 2013)

chipdouglas said:


> I was just about to pull the trigger on a TN30, but I'm going to wait until I've read some more about this issue. Too bad.



Visit BLF and type in its search bar 'TN31 flickering problems'... and wander around, plenty of similar problems


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## chipdouglas (Mar 18, 2013)

BeastFlashlight said:


> In your research did u also consider Nitecore TM26? Just wondering because for awhile I couldn't decide between TM26 and TN30 XM-L2



Thanks for bringing the Nitcore TM26, as I wasn't aware of it. I'd been out of the loop for more than a year because of health issues.


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## BeastFlashlight (Apr 18, 2013)

Any opinions about putting an MTG2 into TN31? (Even if the only option is direct drive)


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## wyoben (Dec 31, 2013)

Thank you for the great review. Do you think you will be doing one on the TN32 anytime soon.


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## bdogps (Jan 12, 2015)

Thrunite is now selling this torch for 100$! http://www.thrunite.com/thrunite-tn31-xm-l2/


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## timsatx (Apr 14, 2015)

It looks like there is a further update. Thrunite is now selling this unit for $88.95. They are no longer shipping it in an aluminum case. It is cardboard like their other items, or at least like my TN12 came in (just bigger ;-) ). It also appears to have more lumens. It is now 1346 instead of the 1147 it was.


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## selfbuilt (Apr 14, 2015)

timsatx said:


> It looks like there is a further update. Thrunite is now selling this unit for $88.95. They are no longer shipping it in an aluminum case. It is cardboard like their other items, or at least like my TN12 came in (just bigger ;-) ). It also appears to have more lumens. It is now 1346 instead of the 1147 it was.


Yes, part of that is no doubt the move to XM-L2 from XM-L on the original version I reviewed (although there may have been circuit changes as well, to boost the output). It appears that Thrunite is positioning this as a more "budget" version of the the higher output, copper-heatsink TN32 thrower.

:welcome:


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