Review: Thrunite TC15, a powerful single-emitter EDC flashlight with USB

This Thrunite TC15 was provided by Thrunite for review. Try coupon code "20%" to save 20% on some products at thrunite.com including the TC15 as of this writing. The TC15 is also available on Amazon (affiliate link) from Thrunite Direct, often for a lower price than thrunite.com.

A full album with extra images is available at https://imgur.com/a/No3CePh

Quick Review

The TC15 is a USB-rechargeable general-purpose and everyday carry light from Thrunite with unusually high output for its size. It's powered by a single 18650 rechargeable battery (included), uses a Cree XHP35 LED and advertises an output of 2300 lumens and throw distance of 246m - figures it actually achieves. Despite its similar appearance, my contact at Thrunite assures me the TC15 is not a replacement for the Neutron 2C, rather, both models will remain available for the forseeable future. The Neutron offers a more versatile set of features, while the TC15 focuses on high output.

That output will be front and center in most discussions of the TC15. Several manufacturers have made less impressive performance claims for lights using the XHP35 and failed to meet them. The TC15, however does exactly what Thrunite says it does, at least, it does when the LED is centered properly. Mine arrived off-center and fell a little short until I adjusted it, which is not a problem I've seen in a Thrunite product before. There are five brightness levels plus a hidden strobe, and shortcuts from off to the lowest, highest, and last-used. A single click of the button is always on/off. The metal button is neither recessed nor very prominent, making it a little hard to find by feel. A red/blue LED in the middle of the button provides a low battery warning. Charging, from a suitable USB wall wart takes 3:15 hours.

The TC15 is a strong value for an all-inclusive rechargeable light, coming in at $60 on thrunite.com, often less on Amazon, and frequently having discount codes available. People who prefer smooth brightness adjustment instead of fixed modes, or the option to shorten the light and use a smaller battery may prefer the Neutron 2C. Those focused on maximum performance will prefer the TC15. Just keep in mind "turbo" is a burst mode that produces too much heat to be sustained. The TC15 will, however make around 1000 lumens as long as the battery lasts

Pro/Con

  • + High output
  • + All-in-one package - arrives ready to use (just remove the plastic from the end of the battery)
  • + Convenient user interface with shortcuts and simple on/off
  • + High efficiency
  • + Low price/good value
  • - Low CRI
  • - Centering and lack of thread lubrication on this sample should not have passed QC
  • - Not waterproof with USB cover open
  • - Button can be hard to find by feel

Ideal use cases

  • Everyday carry
  • Camping/hiking
  • Travel

Unsuitable use cases

  • Police/self defense, due to the switch being hard to find by feel
  • Medical, due to average color rendering

Details and technical analysis

Versions

The TC15 is available in cool white and neutral white. This is the cool white version.

Accessories

The TC15 includes a battery, USB cable, pocket clip, lanyard, holster, spare O-rings, spare USB covers, and spare switch seal. The holster has a sewn belt loop; it is not readily compatible with MOLLE or similar webbing systems.

User interface

State Action Result
Off short press last-used (of low, medium, or high)
Any (except max) double click max
Off long press min
On short press off
On hold cycle low/medium/high
Max double click strobe

Unscrewing either the tailcap or the head of the light a quarter turn locks out operation and eliminates standby power consumption.

Output and runtime

Advertised performance is with a Thrunite 3100 mAh 18650 battery. Testing was performed using a Sony VTC6 3000 mAh 18650 battery unless otherwise noted.

Mode Advertised Lumens Estimated Lumens Advertised throw (FL1 meters) Estimated throw (FL1 meters)
Firefly 1 1 5
Low 25 27 26 27
Medium 250 256 81 78
High 1050 1055 166 161
Turbo 2300 2343 246 235

After fixing the centering, I measured 247m throw. More on that later.

Mode Estimated lumens Graph Advertised Runtime Time to 80% Time to 50% Time to 10% Tailcap current (mA) Efficiency (lm/W)
Standby - - - - - 8 years 0.043 -
Firefly 1 - 41.5 days - - 43 days 2.9 -
Low 27 - 68 hours - - 68 hours 44.1 -
Medium 256 graph 6.5 hours 6 hours 6 hours 6 hours 420 141
High (Thrunite battery) 1055 graph 90 minutes 28 minutes 85 minutes 85 minutes 2350 110
Turbo 2343 graph 2 + 83 minutes 80 seconds 2.2 minutes 66 minutes 7600 109

I should note that while the time to 80% on high is technically 28 minutes, output stays within 1% of that for 66 minutes.

Additional graphs

Light quality

The TC15 is designed for output rather than light quality, however the beam is much better looking than most lights using the new XHP50.2, XHP70.2, XP-L2 and XP-G3 LEDs from Cree. The hotspot is a pure white, with a bit of green in the corona and a bit of purple in the spill. It's fairly typical of a domed XHP35.

Even after adjusting the centering of the emitter, I could see a slight darkening at the center of the beam on white walls at longer distances. It was not noticeable under any other conditions.

White wall

  • https://imgur.com/sD1kzL8.jpg
  • https://imgur.com/vxzWO4h.jpg - vs BLF 348 219B

Outdoor

Color rendering

Despite being the smallest of these, the TC15 has the most output by a large margin and nearly keeps up with the much larger Convoy in terms of throw.

Construction

The TC15 is well-machined with no visible tool marks and smooth exterior anodization. There is some discoloration inside the battery tube. The threads are trapezoidal in profile and smooth to operate. This is a well-made light in general, however my sample did have a couple issues I'm not used to seeing from Thrunite.

First, the emitter was not properly centered. The head of the light is assembled with permanent threadlocker, implying that users are not expected to need to open it and make adjustments, but I had to do so to properly focus the beam and achieve the rated throw distance.

Second, there was no lubrication on the threads and o-rings. This did not keep them from working properly, however I would be concerned about sustained immersion in water. My brief test suggested water might eventually seep past the o-rings and threads if not lubricated.

After adding lubrication. I am confident in the TC15's waterproofing, and conducted runtime testing using water immersion for cooling. The TC15 is not, however waterproof with the rubber USB cover opened while some competing lights are.

Ergonomics

The TC15 is comfortable in the hand and pocket, and comparable in size to most lights with the same battery and USB charging. It is, however noticeably longer than the smallest 18650-powered EDC lights. The pocket clip has sufficient ramp for easy insertion and sufficient tension to hold securely. About 15mm of flashlight is exposed from the pocket, an amount I find makes access easy without being overly prominent.

The switch is held in place by a raised, textured bezel that provides some feel with bare hands. It's fairly difficult to feel with gloves. I'd like to see a more distinct recess here, which would make it both easier to find and harder to press by accident. The lanyard hole on the tailcap can be a mild hotspot in certain grips.

Batteries and charging

The TC15 requires one 18650 battery capable of 8A continuous current. Lower modes may be used with batteries not rated for as much current. The included Thrunite 3100 mAh battery has a semi-transparent wrapper, and the underlying cell is clearly a Samsung 30Q, one of the top rated 18650 cells for high capacity at high current. The included battery has a button top and a protection circuit, however neither is required. Low voltage protection using an unprotected battery shuts off the light at about 2.8V. The light under the switch turns red when the battery is low.

The TC15 will immediately reduce output to about 1800 lumens if battery voltage drops too quickly, as would happen with an unprotected battery not suited to high current. This can sometimes also happen using batteries with a shorter overall length that are rated for the TC15's current because the uncompressed spring adds resistance. Adding rare earth magnets to the end of the battery prevents this. Low-current protected cells such as Thrunite's 3400 mAh 18650 will trip on turbo.

Charge time with a 1.8A rated wall charger was 3:15. That's fairly fast for a USB-charging 18650-powered flashlight. Firefly and low modes are available when plugged in to USB whether or not a battery is installed. It even works with the head detached. A red indicator light indicates charging. Blue indicates charged. Blinking purple indicates an abnormal situation, like no battery installed.

Modification potential

Thrunites are usually pretty easy platfoms for emitter swaps. The TC15 is no exception, and easier than some: I was able to unscrew the bezel with my bare hands - on video, no less. Those familiar with emitter swaps will know what to do from here. I may post a video later for those who aren't.

Options for 12V emitters are more limited than the standard 3V white LED. To make matters more dificult, 5mm emitters like the Cree XHP50 and Nichia 144A don't clear the reflector opening at their base. They may be usable with careful installation, but this reflector is designed for a 3.5mm emitter. I can't recommend swapping anything other than another XHP35 into the TC15.

Aside from warmer tint and my usual unsatiable desire for more vibrant colors, I want the TC15, already the farthest-throwing pocketable flashlight in my collection to have more throw. Most of my existing EDC collection leans floody, which is usually good for EDC, but leaves me with an unmet ~~need~~ want.

Fortunately for me, there's an XHP35 that gives me exactly what I want the TC15 to do: the 80 CRI, 4500K Easywhite XHP35 HI that I usually put into XHP35 lights. Here's what that looks like:

  • White wall https://imgur.com/06kPGkH.jpg
  • Versus BLF 348 https://imgur.com/fXbzhuc.jpg
  • Outdoors https://imgur.com/dPoz5ni.jpg

Recommendations to the manufacturer

  • Consider an XHP35 HI version for more throw
  • Consider using the split battery tube from the Neutron - the latest generation of INR 18350s can handle the load
  • Consider a body design with a recessed switch next time the TC15 and Neutron bodies are revised