Thrunite TH20 Flashlight Review


Thrunite asked if I’d like to review another of their goods, this time the TH20 Headlamp. I have never even had a headlamp in this style, so I figured why not! Truth be told I’ve never even seen an AA headlamp like this whatsoever, so it’s an interesting exploration.

Official Specs and Features:

  • A high output headlamp with max output of 520 lumens in turbo mode powered by one Li-ion 14500 750mAh battery.
  • The logarithmic scale brightness adjustment system allows any brightness from 1.6 lumens to 250 lumens. Furthermore, the TH20 features a built-in SOS signaling mode which is important when roaming out in the wild or confronting dangerous situations.
  • Unlike other light-weight headlamps which are made with plastic, the TH20 is made with aircraft grade aluminum which gives it exceptional durability and excellent heat dissipation allowing it to maintain high output for extended periods of time.
  • The advanced design gives the TH20 a light weight of 76g (battery excluded).
  • The TH20 can also use an easy to get AA battery which makes it a great choice for daily reading, camping and a tool light when you want your hands free.


LED: CREE XP-L V6 LED with a lifespan of 20+ years of run time.
Mode & Runtime (Tested by one Eneloop AA 2450mAh NIMH rechargeable battery):
-Firefly (0.3 lumens, 14 days)
-Infinity Low (1.6 lumens, 21 hours)
-Infinity High (230 lumens, 95 minutes)
-Turbo (250 lumens, 93 minutes)
Batteries Applicable: 1x AA battery, 1x 14500 battery.
Working voltage: 0.9-4.2 V.
Reflector: Orange Peel.
Peak Beam Intensity: 1120 cd
Beam Distance: 67 m (max.)
Dimensions: 70 mm * 24.5mm
Weight: 76g (without battery).
Waterproof: IPX-8 (2 m)
Impact Resistance: 1 m.
Material: Aircraft grade aluminum body with premium type III hard anodized anti-abrasive finish.
Accessories included: O ring, spare rubber slot.


There are two versions: A neutral white (as seen in this review) and a cool white version.



(This is a new section, which I feel like is pertinent information for you when you evaluate the rest of the review, and particularly in comparison to other lights. Value is important, and it’s also important to have expectations realistic to a given price range.)

Short Review:

This is a fine little headlamp with a neat UI.

Long Review:

What’s Included

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Here are the photos, and beamshots, and a runtime. I ended up basically doing two photo shoots for this light so there are a bunch of duplicates (ish) in that album.

Package and Manual

The TH20 is tightly packaged

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in an almost-cube cardboard box.

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There’s a bit of printing

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on the outside (including a QR code,

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and a bit of foam padding on the inside. It’s all very snug, and protective. I like these packages a lot.

The manual is one big sheet with and 6 languages.

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I’d love for the fold outs to be done so that each language would be on it’s own opened area, but as it stands, you basically just unfold the whole thing and look at the section in your language. It’s ok, not great. The manual does describe the UI and features of the light adequately, in any case.

Build Quality and Disassembly

There are no complaints about the TH20 build quality. The anodizing seems quality, and the threads are well lubed.

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The silicone mount for the headstrap is of normal quality (maybe even “beefy”)

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and in the event of issues, there is of course a backup. The tailcap has a spring

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(but no magnet) and ‘head’ side has a contact (but no spring), and is also printed

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on the outside telling how to open the light (but not which way to insert the cell!!). The knurling on the tailcap is also very nice, making unscrewing it very simple.

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The headstrap is a soft stretchy band, and the silicone holder makes minimal contact with the forehead.

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The band is quite adjustable, too.

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I was surprised that the “head” side of this light (the positive end) didn’t unscrew.

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Same as the Thrunite C2 charger – looks like it’ll unscrew, but in fact doesn’t. Not that this is a problem as far as disassembly is concerned: The emitter is on the side of the body of the light. It is held in place by a screw down bezel, which could most likely be unscrewed with the proper tools.

The TH20 will “head” and “tail” stand but the button protrudes enough that the light sits unevenly

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on the head side. Completely flush on the tail side, though.

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The TH20 is short, at 70 mm, but it does have some girth to it, at 24.5mm. It’s not much longer than an AA cell, and really not all that much wider, either. Though, there’s extra room in the cell tube for a bit of electronics. So the tube is slightly oversized for this. The cell is actually held in place by a plastic shroud, which is not removable.

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The included headstrap is the only option for retention on this light. I typically carry at least one angle light in the bunch of lights I carry day-to-day, and the TH20 thwarted my efforts to use it in that way. This light is really *made* for and *meant* for use in the headstrap. Everything about it works best in the headstrap. To wit: there is no magnet or clip or lanyard, or anything else for use with this light. That makes perfect sense for the TH20, though.


This headlamp works with AA sized cells.

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This includes AA primaries and rechargeables like Eneloops, and also 14500 button top cells (not sure about flat tops, I don’t have any of those). However in my testing (so, unofficially) performance is no better with a 14500. The runtime is slightly different (with a much harder cutoff using the 14500), but performance (ie output) is approximately the same.

Furthermore, the Th20 does not seem to have any low voltage protection. High using the 14500 cell, cutoff at 0.46V. I primarily use an unprotected 14500, so that’s….. not good. AA (Eneloop) cutoff was around 0.88V – I’m thinking Eneloops may have their own protection, tripping at around this voltage, because I’ve seen test after test with the Eneloops shutting off around 0.88V. I haven’t been able to confirm this, however.

In any case, the lack of low voltage protection, and lack of any warning whatsoever concerns me for something whose intended use is directly on my forehead.

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The cell is inserted with the positive terminal into the headlamp. Positive goes on the switch end.

User Interface and Operation

There’s a single silicone button on the head end of the light (again, where “head” is the positive terminal side). This switch protrudes just enough to keep the light from head standing level, and the hatching on the switch is quite grippy.

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State Action Result
Off Click On
On Click Off
Off Hold Firefly
Firefly Hold “Infinity” Cycle L>H*
Any Double Click Turbo
Turbo Double Click SOS

* When holding the button to ramp from Firefly to High, releasing the button switches the ramp direction. So if you’re on your way L>H, and stop and hold again, the light will cycle H>L.


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When the light reaches either extreme (H or L) it’ll flash 3x to demonstrate that’s the extreme, and it’s about to start going in the other direction.

LED and Beam

The emitter is a Cree XP-L (V6) and has a shallow orange peel reflector.

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This shallow reflector makes the hotspot not very hot, which is probably just about ideal for a headlamp. The hotspot is reminiscent of a TIR, but with much more spill.

Beamshots, Runtime, and Lux Measurements

Brand Thrunite
Model TH20
Emitter Cree XP-L NW
Emitter Notes V6
Runtime 14500, AA
Beamshots [0.3″, f/8, ISO 100, 5000k] 14500, AA
Claimed Lumens (lm) 520
Lux (Measured) 92, 111
At (m) 2.639, 2.524
Candela ([Calculated] in cd 640.72, 707.13
Throw ([Calculated] (m) 50.62, 53.18
Throw (Claimed) (m) 67

14500 in Bold.

Random Comparisons and Competitive Options….

There are a fair few headlamps in this style (AA style, generally), which also accept 14500. Armytek has a bunch (all the Tiara A1’s for example), Zebralight has a few (all the H52’s for example), and I expect there are others. None of those lights compete with this Thrunite TH20 on price alone, and also I think the UI on this TH20 is unique enough to set it apart. The other lights do have varying emitter options, and are not strictly dedicated headlamps (necessarily) – they’re more of “angle lights” and could serve multiple functions (pocket carry, for example).


When I first saw this light, I thought “great, I’ve been wanting to try an 18650 headlamp in this style!” Then I read some more and saw it was AA and got a little disappointed. But it’s a fine light, and users who prefer AA style lights should definitely consider this Thrunite TH20.

What I like

  • Build quality is good
  • UI is unique and useful
  • Ramping UI is good
  • The headstrap is nice and comfortable

What I don’t like

  • Seems slightly bulkyfor an AA
  • UI is good if you’re used to it. Can take time to get used to it.
  • That the performance on AA and 14500 seems …. the same is strange.

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Up Next

My next review will be of the Olight H1R Nova. Stay tuned!!

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