Warning: even more pic heavy than usual!
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.
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.
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.
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.
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.
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.
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.
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.
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). 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.
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.
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.
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.
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.
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.
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.
TN31 provided by Thrunite for review.