Thrunite TN12 Pro Review – Instant-Turbo on a Budget

Contents

The Boring Stuff

Thrunite sent me this light in exchange for an honest review. Here is the official product page and here is the Amazon listing where it’s going for a little over $40 after a coupon at the time of writing. Below are the official specs.

What comes in the box?

TN12 Pro comes in one of Thrunite’s excellent cardboard boxes. It’s a thick, two-piece box with some basic printing to let you know what’s inside. Inside you find the light nestled in a nice foam insert to keep it protected. I’m always impressed with Thrunite’s packaging because it feels high quality, but in a way that isn’t wasteful just to make a nice unboxing “experience”. The following items are included in the box:

  • The light itself
  • A battery (installed in the light)
  • A lanyard
  • Spare O-Rings
  • Spare port cover
  • Spare button insert
  • USB A-to-C charging cable
  • A belt holster

Design & Construction

The design is a fairly typical dual-switch tube light and I think it looks good. There’s some milling on the body tube that looks nicer and is less aggressive than the knurling on its predecessor, TN12 V4. It’s a cool looking light without screaming “tactical”. There are some mild crenulations in the bezel that will allow some light through if you set it face-down and it gets activated.

Build quality is a little bit above average, like most Thrunite products. The anodizing is nice and evenly applied. It’s a very deep black, which you can see in the size comparison photo in the next section. The pocket clip had some nicks when I took the photos but those are probably just from me carrying the light around. The tail threads are unanodized which will improve reliability on a dual-switch instant-turbo light like this. They are nicely machined and well lubricated but they’re a little hard to start. The body tube and head are glued, but that helps with reliability and you wouldn’t be changing the driver out on this light anyway. My only real quality-qualm is the side switch, which I’ll discuss more in the switch section.

Size & Measurements

Convoy M1 | TN12 V4 | TN12 Pro | Sofirn SD02B | Noctigon KR1

MeasurementMeasured (mm)
Bezel Diameter25.0
Maximum Head Diameter27.0
Length131.2
Tail Switch Diameter14.2
Tail Switch Proudness0.0
Side Switch Diameter8.0
Side Switch Proudness0.0
Lens DiameterUnable to measure
Lens ThicknessUnable to measure
Reflector Hole DiameterUnable to measure
Reflector DiameterUnable to measure
Reflector HeightUnable to measure
MCPCB SizeUnable to measure
Body Tube Diameter (internal) 19.0
Body Tube Diameter (maximum)24.5
Body Tube Diameter (mode)24.0
Ride Height (sticking out of pocket)22.3
Pocket Clip Space (for pants material)3.1
Pocket Clip Space (at mouth)1.7
Pocket Clip Width7.0
Pocket Clip Thickness1.0
Pocket Cip Slot Width6.1
Pocket Clip Slot Diameter22.0
Tailcap Diameter25.5
Tailcap Length27.6
Driver DiameterUnable to measure
USB Port Width11.5
USB Port Depth2.3
USB Port Height6.9
Included Battery Length70.5
Included Battery Diameter18.8

Weight without battery: 89g
Weight with included battery: 143g

User Interface

This light basically has two UI’s, one for each switch.

Side Switch: The actions are # of presses followed by a hold (H) or a release (C). So, “1C” is one click and release. “2H” is two clicks but you hold down the last one.

StateActionResult
Off1COn (mode memory)
Off1HFirefly (not memorized)
Firefly1HLockout
Any (except lockout)2CTurbo
Any (except lockout)3CStrobe
On1COff
On1HCycle Mode (low-med-high, memorized)
Side Switch UI

The side switch UI is good overall. There are some quirks though.

Unlike other UI’s, it does not wait to see if you will click again before taking action. So, a double click from on turns the light off on the first click and then goes to turbo on the second click. It’s a little weird coming from other lights but you get used to it.

If you sit on medium mode for more than a second, holding the button down will go to low instead of high. That’s weird, inconsistent, and I don’t like it. I think this is Thrunite’s way of not making you go through high to get to low, but there’s a much better way to do that that all the other manufacturers have already figured out.

Holding from Firefly goes to lockout. It should go to low. That’s how the vast majority of other e-switch UI’s work and its a much better solution for going back to low than the weird time-based thing Thrunite does. Lockout should be accessed via 4 clicks instead.

Tail switch:

StateActionResult
Any (except lockout)Half-Press TSMomentary Turbo
Any (except lockout)Click TSTurbo
TurboClick TSOff
Tail Switch UI

Double Lockout: There are two lockouts on this light. 1H from Firefly goes to normal lockout. 1H from lockout will exit. But there’s also double lockout. Double lockout is accessed by clicking the tailswitch on while you’re already in normal lockout. It prevents holding the side switch from exiting lockout. It’s a bit convoluted and I wish Thrunite had used 4 clicks of the side switch to enter and exit lockout instead, which would eliminate the need for this double lockout function.

Notes: If the tail switch is engaged, the side switch does nothing. If you turn the light on with the tailswitch, clicking the side switch won’t do anything. If you click the tailswitch during lockout, the side switch won’t do anything. If the light is on by the side switch, then you use the tail switch, when you release the tail switch the light will turn off rather than going back to the mode it was on.

Modes, Brightness, Throw, & Tint

Disclaimer: Lumen measurements were taken on a Texas Ace 3.5″ Lumen Tube. A candela measurement was taken at 10 meters with an Opple Light Master Pro on the highest brightness, and other candela figures were calculated relative to that. CRI, CCT, & DUV data was taken for each mode from a few feet away at the center of the hotspot with the Opple Light Master and Waveform DUV Calculator. Runtime tests were performed with the Ceilingbounce app on my smartphone. All of these tests were performed with a fully charged included battery unless otherwise specified. I cannot measure moonlight directly, so moonlight readings are calculated based on the brightness relative to the next-lowest mode. None of this is professional equipment, so take all of these measurements with a grain of salt.

Level Lumens (@ Turn-On)Candela (@ Turn-On)Throw (meters)Color TempTint (DUV)
Turbo19603800039066100.0041
High5401046920563400.0058
Medium220426513161200.0076
Low519896361600.0075
Moonlight0.47.85.657200.0123

Mode Spacing: is good. There are no oddly large or small jumps between modes.

How does it compare to the official specs? both my lumen and candela measurements beat the official specs by a bit so they seem accurate enough to me. That could just be the margin of error for my testing equipment or it could be that I measure at turn-on and Thrunite may be measuring at 30 seconds.

Runtime

Performance: Turbo starts out just under 2000 lumens and starts thermal stepdown just before the 2 minute mark. Thrunite claims Turbo lasts for 7 minutes, but that’s how long it takes to completely settle, not how long Turbo actually lasts. Except for the brief Turbo blip in the beginning, high and Turbo mode look exactly the same. Thermally stable output is just under 500 lumens.

LVP: I don’t think it’s present, but the switch will warn you when voltage is low. I ran my Medium test for twenty four hours to see if the light would ever shut off. I ended the test at 24 hours because it had been running at a moonlight level for over twelve hours at that point. When I ended the test, the cell was at 2.53V which is pretty low. Any LVP built into the light should have cut off at 2.7-2.8V under load. What troubles me is that the protection circuit in the cell hadn’t tripped by that point either. With that said, it ran for hours and hours and hours at a moonlight level so the odds of you accidentally over-discharging the cell are very low.

Driver & Regulation

The body tube is glued to the head so I wasn’t able to get a great photo of the driver. It appears to be using one circular PWB like most lights, plus a daughter board that sticks up into the head. Based on my regulation testing, I believe this is an unregulated FET driver. That’s a little disappointing coming from Thrunite, but it’s not unusual at this price point with all the other features offered in TN12 Pro.

Regulation is poor. All levels are heavily affected by battery voltage.

Note: All regulation measurements are taken at turn-on so they do not reflect any thermal or low voltage stepdowns that may occur. A value of 0 indicates low voltage shutoff immediately upon activation.

Thermal regulation: is present and works ok. The thermal ceiling is higher than I’d like so the light is too hot to hold when thermally saturated, but it doesn’t ever reach concerning temperatures.

PWM: No PWM is visible to my eye but it is faintly audible on High mode. I did some testing on each mode with an Opple Light Master III and found PWM on Low, Medium, and High modes.

Parasitic Drain: 68 microamps. That will take over 5 years to drain the included battery. Despite the tailswitch being mechanical, it’s connected to the driver like an e-switch. That means turning off the light won’t eliminate parasitic drain. Thanks to the unanodized tail threads, neither will loosening the tailcap. The battery needs to be completely removed to totally eliminate parasitic drain.

Emitter & Beam

TH12 Pro uses a Luminus SFT40 LED, which is a big upgrade from the domed Cree XPL V6 LED used in the older TN12 V4. SFT40 provides a lot more brightness and a lot more throw. It only comes in a 70 CRI cool white configuration from Luminus though, so don’t hold your breath for a neutral white version of TN12 pro.

CRI (Ra): I measured 63-68 CRI with my Opple Light Master Pro.

Unfortunately, I was unable to remove the bezel. I suspect its glued. This is a real shame because my light came with a little black speck on the LED and I can’t clean it off because the bezel is glued. It doesn’t affect performance at all but it bugs me and I’d like to be able to fix it. It would be nice to be able to do emitter swaps too, but no dice.

The hotspot is narrow with a tiny dark spot in the middle, but you don’t notice during normal use. It’s possible that’s only a problem on my sample because of the speck on the LED. There’s some smooth corona that transitions to bright spill and that all looks great. Outside the spill though, there are multiple magenta rings from the AR coating on the lens. It’s not the prettiest thing but it doesn’t hinder the functionality of the light at all.

TN12 Pro | TN12 V4 NW

In the beamshots above, the trees where I’m aiming the hotspot are 175M away. In the beamshots below, the park bench where I’m aiming the hotspot is 42M away.

TN12 Pro | TN12 V4 NW

Switch

The most compelling feature of TN12 Pro is its switch setup. The tailswitch is a forward clicky mechanical switch that always goes straight to Turbo and allows for momentary activation. The tailswitch can be easily disassembled with a pair of snap ring pliers inserted into the holes on the PCB. You could even swap the black switch boot out for one of these colorful ones if you wanted.

The side switch works like any normal e-switch and is completely independent of the tailswitch, allowing you to access all the other modes. It’s plastic with a glowing indicator in the center. While in use, blue means the battery charge level is good. Red means it’s low. Flashing red means its critically low.

Remember when I said my only quality-qualm was the side switch? It rattles. When you touch it you can feel it wobble around and when you shake the light you can hear it. It does not convey quality.

This particular dual-switch setup where the two switches work independently requires a dual body tube. The outer tube is for structural support and to carry power from the battery to the driver. The inner tube carries the signal from the tailswitch so the driver knows when it’s been activated.

Carry & Ergonomics

Ergonomically, TN12 Pro is good. There are no hotspots or sharp edges. The clip provides a good index point.

Thrunite includes three carry methods: a pocket clip, lanyard, and belt holster.

The pocket clip is pretty good and is a significant upgrade from the one on TN12 V4. There’s not much ramp at the front but it still slides over my pockets easily. It lands on a smooth spot on the body tube so it won’t tear up your pockets. It’s not what I’d call deep carry but it carries deeper than a lot of other tactical EDC lights. It’s bidirectional too so in a pinch you can clip it to a hat. Most importantly, it’s wide enough to actually fit pocket/hat brim material inside the loop-over parts of the clip. Some older clips from Thrunite were too narrow so despite being “deep carry” you couldn’t actually get the light to fully seat in your pocket. A good clip is critical and Thrunite nailed this one. My only gripe is that the tailcap fins & the side switch don’t align, so I can’t rotate the clip to align with both. I have to choose between lining it up with the tailcap or lining it up opposite the side switch.

The included belt holster is fine. It’s got a velcro closure and a d-ring at the top. It feels a little flimsy and you have to remove your belt to thread it on, but at this price point I’m just impressed one is included at all, so I’ll take it. The included lanyard is high quality and has a little adjustable tightener to keep it snug on your wrist.

Tailstanding works fine without a lanyard installed. There is one lanyard hole on either side of the tailcap, so attaching a lanyard will interfere with tailstanding. In the future, I’d like to se Thrunite put two lanyard holes side by side (like the photo below of another light I reviewed). That allows the lanyard to be tied around the material between the holes instead of tied around the material between the hole and the outside of the light. It prevents a lanyard from interfering with tailstanding.

Batteries & Charging

Thrunite includes a 3400mah protected button top 18650 cell. I measured its capacity on my SkyRC MC3000 at 3240mah. Its a fine cell but it’s unusually long, even for a protected 18650, at 70.5mm. I also tested with an unprotected flat top 18650 and it worked just fine as well. Notably, two CR123A’s are not supported in TN12 Pro like they were in previous versions of TN12. Presumably that’s because this Pro version is using an inferior FET driver while previous versions used Buck drivers that could handle the extra voltage.

Charging is facilitated by a USB-C port on the side of the head. Most lights have the charging port directly opposite the button, but Thrunite put this charging port 90 degrees from the button. Both A-to-C and C-to-C cables work just fine. There is no powerbank function. Charging takes about 2.5 hours and stops at 4.13V which is oddly low. There’s nothing wrong with that and some users will argue that it extends the lifespan of the battery. It does mean you’re probably going to miss out on just a few minutes of runtime though. Only Firefly mode is available when charging. The side switch glows red when charging and glows blue when fully charged.

I strongly dislike this charging port cover. It’s not nearly secure enough and it’s difficult to get it seated properly. It’s a little bit too long for the USB port, so it takes some fiddling to get it seated. It’s flat on the sides instead of having a lip around the bottom edge so there’s nothing but friction holding it in place. The tab on the end sticks out a fair bit and it’s very grippy, so it often grabbed my pocket and opened when I pulled the light from my pocket. There’s no slack in its connection to the light either, so when rotating it out of the way for charging it will sometimes kink instead of rotating. This port cover is consistently annoying, whether you use the integrated charging or not.

Just for comparison, look at the port cover below that Sofirn uses on a several models. It’s got a lip around the whole bottom edge that fits into a milled slot around the port. That holds it in place very securely. It also makes it very distinct when the cover is fully seated because it will sort of pop into place. The tab is a lot less grabby too, so it doesn’t pull open in your pocket. The port cover lifts almost completely out, allowing you to rotate it around with ease for charging. This is how you make a port cover.

Competition

Here are some lights in the same class and how they compare.

Wurkkos FC12: the LED, brightness, throw, overall size, battery, pocket clip, charging, and price point are all very similar. FC12 has a much better charging port cover, stepped modes or smooth ramping, and no dedicated turbo button. It uses the tailswitch for on/off and uses the side switch for mode changes. It’s also available in multiple body colors

Thrunite BSS V4: (ostensibly) brighter led with a wider hotspot and a lot less throw, Micro-USB instead of USB-C, worse clip, longer, better driver, includes removable red lens and strike bezel, more expensive, available in multiple colors, same instant-turbo tailswitch

Acebeam EC35 Gen II: high CRI LED available (Killzone exclusive), same instant-turbo tailswitch, can be used as a powerbank, worse clip, better driver, more expensive

This section is not comprehensive. If I didn’t include a particular light here, it doesn’t mean it’s bad or doesn’t deserve to be here. I simply cannot list every possible competitor.

Conclusion

At the time of writing, TN12 Pro is the cheapest and throwiest EDC-size light with an instant-turbo switch feature. That combined with the included battery, good UI, and integrated charging make it a pretty compelling package. If you don’t mind the chincy port cover and poor regulation, this could be a great option for you.

Thanks to Thrunite for sending me this light for review!