Review: Wowtac A2S, a budget right-angle headlamp with USB battery

This Wowtac A2S was provided by Wowtac for review. The A2S is also available on Amazon.

A full album with extra images is available at

Quick Review

Wowtac is a budget brand affiliated with Thrunite offering a line of 18650-powered flashlights, with an included 18650 battery that has a direct USB charging port, starting at $20. The A2S is the right-angle/headlamp version with higher output and a larger battery capacity for $30.

The A2S features a 3400 mAh battery, 1050 lumens and 150m FL1 throw, making it competitive with most of the right-angle segment. It fell a little short of the claimed 182m throw, but otherwise performs as advertised. The UI offers shortcuts to the highest, lowest and last-used modes with a single press for on/off. Neutral white is available, though it's not the nicest looking neutral white I've seen with some noticeable green, and tint shift across the beam. A headband is included, but not a pocket clip, making the A2S more headlamp than EDC as it comes. A Thrunite TN12 pocket clip will fit.

I own several right-angle lights, and while the A2S is not my favorite of them, it costs a third what higher-end models do. Those often don't include a battery or charging solution, so the price difference can be larger still. The A2S is an incredible value, and any potential shortcomings must be considered in light of the fact that it costs $30 for an all-inclusive package. If you don't already have batteries and chargers, and you want a headlamp for less than $50, the A2S is almost certainly your best option. The all-inclusive package makes it a good gift or recommendation for people not interested in flashlights as a hobby.

  • + Excellent value
  • + User interface has shortcuts
  • + Simple on/off
  • + Very high output for this market segment

  • - Missing O-ring on my sample

  • - Tint isn't especially nice, even in NW
  • - Low-CRI
  • - Pocket clip not included

Who should buy the A2S:

  • People who are price-sensitive
  • People who don't have an existing stock of batteries and chargers
  • People who want to swap emitters in right-angle lights

Who should not buy the A2S:

  • Tint snobs who don't want to swap emitters
  • CRI babies who don't want to swap emitters

Details and technical analysis


The A2 series includes:

  • A2 (CW only): XP-G2 emitter, 550 lumens max, 2600 mAh battery, $20
  • A2S (CW): XP-L emitter, 1050 lumens max, 3400 mAh battery, $30
  • A2S (NW): same as above, but neutral white around 4500K CCT, $30

This is the A2S NW.


The A2S includes a headband, two spare O-rings, a Wowtac branded 18650 with USB charging port, and a MicroUSB charging cable.

Modes and user interface

State Action Result
Off Short-press Last-used
On Short-press Off
Off Long-press Firefly
Any (exc turbo) Double-click Turbo
Turbo Double-click SOS
On Hold Cycle through the three middle modes L->H

Changing modes within a few seconds of a previous mode change advances from the current mode, but after waiting a while, the cycle will start from low. The Thrunite TC12 v2 is known to have the same behavior, and I find it thoughtful. Waiting a bit longer for a higher mode is better than overillumination that impacts dark adaptation. Turbo is always a double-click away if high output is desirable in a hurry.

Unscrewing either the head or tail a quarter turn disconnects the battery, reliably locking out the light from accidental activation and eliminating standby power drain for long-term storage.

Output and runtime

Advertised output and runtime is with the included Wowtac 3400 mAh battery. Test data was collected with a Sony VTC6 3000 mAh battery unless otherwise noted.

Mode Advertised Lumens Estimated Lumens Throw (FL1 meters) Graph Advertised Runtime Time to 80% Time to 50% Time to 10% Tailcap current (mA)
Firefly 0.3 - - - - - - 2 years 0.1
Firefly 0.3 - - - 59 days - - 38 days (calculated) 3.27
Low 24 10 16 - 4 days - - 4.5 days (calculated) 28
Medium 126 106 48 graph - - - 38 days (calculated) 134
High 420 390 92 graph 4.5 hours 80 minutes 2.4 hours 3.6 hours -
Turbo 1050 1040 150 graph 2.7 hours 3.6 minutes 56 minutes 2.3 hours -
Turbo (Wowtac battery) 1050 - - graph 2.7 hours 3.6 minutes 37 minutes 2.7 hours -

Runtime with the supplied battery is exactly as advertised and significantly longer than the difference in capacity would suggest. Time to 50% tells the story: the VTC6 maintains higher voltage, and therefore higher output for longer.

There is low-voltage protection at about 2.6V.

Light quality

Light quality is a weak point of the A2S, despite coming in the popular 4500K neutral white, which should look similar to mid-afternoon sunlight. There's a significant green off-tint to the hotspot, and the corona around it is even more green. The spill, on the other hand tends toward purple, yet somehow still has a greenish tinge. The green tint is stronger in lower modes, but always present. CRI, a measure of color quality is unspecified, but probably around 70. CRI over 90 is available in LEDs, and 100 is the theoretical maximum.

Comparison: Wizard Pro 144A:

The green off tint is noticeable outdoors, and I find it distracting. It's excusable at this price point, but LEDs producing nice looking light are not expensive. They usually give up a little output, but human vision can barely detect moderate differences in output, while significant differences in color are easy to see.

There is PWM in lower modes, but it's extremely fast and only shows up when photographing the emitter directly using an electronic rolling shutter like a smartphone. It is not visible to the naked eye under any circumstances

White wall

White balance is 5200K for all beamshots.

  • Versus BLF 348 (219B):



For comparison, here's the last scene illuminated with a Nitecore HC30 with a 4000K, 90 CRI Nichia 219C:



The A2S is simply and solidly built, with an all-aluminum body. It uses square-cut threads, which are more durable than the triangular threads more commonly seen in this price range. My sample was missing the head-side o-ring, and unsurprisingly failed a brief immersion test. I installed one of the included spares, after which it had no water ingress when submerged.

Lest there be any suggestion that samples provided to reviewers have unusually good quality control, that is obviously not the situation here.


As a handheld flashlight, the A2S has ergonomics typical of right-angle lights with a top switch. It's comfortable in the hand. The switch is easy to reach with a finger or thumb while still clearing the lens. With an added pocket clip, it's no more bulky in the pocket, carried head-down than the average 18650 light. I do recommend turning the battery tube around to make it sit a little deeper.

As a headlamp, it's similar to other angle lights with rubber holders. That is to say, it's less comfortable than Armytek's plastic mount, but not bad. I could work or hike for hours with the A2S without complaint.


The A2S comes with a Wowtac branded 3400 mAh battery with a USB charging port. I haven't unwrapped it, but it's probably an LG F1L. My Opus BT-C3100 shows 3220 mAh, which is a little low, but in the normal range for that cell. USB charging takes 5.5 hours and does result in the button top getting quite warm to the touch. This is typical of other Li-ion cells with this style of charging port, and the rest of the cell stays at a more comfortable temperature.

Modification potential

It's easy to remove the bezel ring from the A2S using snap-ring pliers. Removing everything down to the MCPCB is straightforward, and the MCPCB itself isn't especially hard to get out. It does require a bit of force though due to the type of thermal paste used. I put a hook made from a nail under the MCPCB on the switch side and pulled straight up.


I've been pretty clear about my disdain for the stock XP-L. Not every XP-L looks as bad, but domed XP-Ls usually aren't any tint snob's favorite no matter the tint bin. This thing needs more ~~Nichia~~ Samsung. After my recent post about Arrow practically giving away LH351D emitters, I suspect nobody will be surprised about this being my choice of swap here.

The LH351D is identical in size and beam pattern, and superior to the XP-L in output and efficiency. Of course, in 90 CRI it does take a bit of an output hit versus a low-CRI emitter: a 6% loss, to be exact. The LH351D makes 1000 lumens at 30 seconds. Most people cannot even detect a 4% difference in brightness with their eyes, much less notice it in a practical sense.

This is a 5000K, 90 CRI LH351D, An a white wall, it's much more even and less green than the XP-L. The closest tint comparison I've seen would be a 5000K Nichia 219C, though the Samsung looks a little less green to my eyes. Testing by maukka shows that this emitter is awesome with CRI comfortably in the 90s, and R9, measuring deep red, over 60. R9 is difficult for LEDs to score well on, and typical high-CRI Nichias guarantee a minimum of 50.

I think the last two photos really drive home the point. The hotspot of the XP-L looks overexposed while the LH351D is clear. There's no difference in camera settings, nor any significant difference in light intensity. The XP-L looks overexposed because there isn't sufficient color information.

If Wowtac were to update the A2S with this emitter as stock, it would be a huge improvement to the light. Traditionally, there has been a significant tradeoff between color quality and output, but not here. The LH351D even costs less than the XP-L. There's no disadvantage I can see to using it. If anyone at Wowtac is interested, the part number is SPHWHTL3DA0GF4RTS6.

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