Convoy 3x21A

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Convoy 3x21A review

Convoy 3x21A specifications

Brand/modelConvoy 3x21A
LED3*Luminus SST40
Lumens6,800 lm
Beam intensity142,500 cd
Battery config.3*21700
Review dateAugust 2021


Convoy is the brand that first brought me into the custom flashlight scene at BudgetLightForum. Convoy didn’t necessarily have the fanciest, craziest, or most tricked-out flashlights ever. Rather, Simon Mao (the man behind Convoy) had a reputation for listening to community feedback and for providing rock-solid flashlights whose value exceeded their asking price. It’s also one of the very few brands that actually sell “hosts” (a flashlight body without LED or driver). But that’s not to say that Convoy doesn’t produce amazing flashlights. On the contrary, I’ve come to expect great built quality even if I’m not getting cutting-edge specs most of the time.

Convoy’s lineup is quickly adopting 21700 batteries (all the rage) and on-board USB-C charging. After much success with the 4x18A (4x 18650 batteries) people clamored for a similar light but with 3x 21700 batteries and a triple-emitter setup. The result? The brand new Convoy 3x21A, which is offered in not only the nice Luminus SST40 but also with the new-on-the-scene SFT40. Let’s see what Simon has cooked up for us.

Package quality.

True to Convoy form, the 3x21A arrived in a very sturdy brown paper-board box lined with foam.  No external branding or other markings, outside of a sticker stating the flashlight model and LED specs.  Inside that box was:

  • Convoy 3x21A
  • Flat-top battery adapter

Yup, that’s it. No lanyard, no o-rings. Not even a manual! Simon wasn’t messing around. You bought a flashlight, and a flashlight is what you got! But every little nicety skipped is money saved, and that carries through to the selling price.

Flashlight in use

The Convoy 3x21A is what’s regarded as a “soda can light”. It’s exactly what you think it might be. Grasp a soda can. Yup, that’s pretty much what it feels like to hold a 3x21A (well, unless the 3x21A is on then in which case it will likely be much warmer than that soda!). This isn’t your “I’ll slide this in my pocket” kinda light. This is a “let’s light everything up” kinda light.

While it looks like it could roll around, the grooves around the head prevent it from rolling too much. The bottom is very flat and therefore tail-stands like a champ. The tail does have lanyard attachment holes, but you better be using paracord to support this weight.

There is a single switch, an e-switch located on the side of the light towards the head.

Build Quality, and Warranty

The Convoy 3x21A is a chunk. There are several beefy heatsink fins around the head. The body tube is covered in rectangular-cut knurling of sorts. The anodization is pretty matte. It’s definitely not the chalkiest Convoy coating I’ve seen, but it is similar to many other black Convoy models I’ve seen recently. As to be expected, the threads are clean, smooth, and square-cut.

The flashlight is very easy to disassemble. The bezel isn’t glued, and can easily be removed in order to access the polished aluminum reflector and LEDs (in case you wanted to swap them). The driver is held in with 2 screws and can be removed. While removing the tailcap isn’t required for operation, it’s easy to do and can be helpful if you want to do spring bypasses. Which you might want to do if you’re chasing the absolute highest lumen output.

I’ve never seen anything official regarding a Convoy warranty. From everything I’ve heard, though, Simon is glad to help if anything goes wrong (like sending out replacement parts, etc) without any problems.

LED, Lens, Bezel, and Reflector

The Convoy 3x21A, at the time of this writing, comes in 3 different LED offerings. The headliner here is the brand-spanking-new Luminus SFT40. That particular LED is currently only available in 6500K, but hopefully, that will change in the future. The SFT40 is commonly described as a domeless (more throwy) version of the SST40. While that is somewhat true, it’s actually built quite a bit differently than the SST40. Initial testing has shown that it’s much throwier without sacrificing many (if any) lumens. That’s pretty incredible. The Convoy 3x21A is also available with Luminus SST40 LEDs in your choice of 5000K (neutral) or 6500K (cool) white LEDs. My review sample arrived with my favored CCT, 5000K.

Those LEDs sit nicely centered in a smooth machined aluminum reflector. The reflector is held in place with a sheet of glass, which is situated in the middle of a smooth stainless steel bezel. That stainless is a great accent piece and can help protect the bezel from dings.

The SST40 that my sample came with (SFT40 were out of stock at the time of ordering, unfortunately) are fairly floody LEDs.  And with 3 of them, you’d expect a fairly floody beam. And that is true, but with as much power as these LEDs are putting out, the beam reaches out a good distance from brute force. When equipped with the SFT40 LEDs, the flashlight is said to have nearly twice the candelas (beam intensity) for even further range.

The 3 SST40’s provide a fairly clean beam with just a small amount of tint shift. Due to the triple-reflector setup, there is a little bit of an interesting flower petal pattern when going white wall hunting.

Dimensions and size comparison

  • Length: 158.4 mm / 6.2 inches
  • Head diameter:  69 mm / 2.7 inches
  • Body diameter:  51.8 mm / 2.0 inches


  • With cells: 780 grams / 28 ounces
  • Without cells: 569 grams / 20 ounces

Flashlights size comparison

New Convoys, left to right: Convoy M21D, Convoy 3x21A, Convoy L7

High Output Lights, left to right: Convoy 3x21A, Fenix LR50R

Driver & User Interface:

The Convoy 3x21A shares the same UI as many recent Convoys. It’s pretty flexible. Not perfect, but at least you have options.  The flashlight arrives from the factory with ramping mode enabled. But I’m not a very big fan of how the ramp was designed: too little time in the “low” range and too much time in the “high” range. It’s possible that the ramp is linear, but that’s not how our eyes interpret light. So I quickly changed the 3x21A over to the stepped mode and am much more satisfied with how it functions.

Modes: Moonlight (0.2%), Low (1%), Medium (10%), High (40%), Turbo (100%)

From OFF:

  • Press and Hold: moonlight mode
  • Single click: turn on in last used mode
  • Double click: turbo
  • Triple click: strobe
  • 4x click: tactical mode (100% only, 4x click to exit)
  • 5x click: battery check (in volts and tenths)
  • 6x click: stepped/ramping mode switch
  • 10x click: lockout enable

From ON:

  • Press and Hold: increase brightness level
  • Single click: turn off
  • Double click: turbo mode
  • Triple click: strobe

Mode memory:

  • Yes, mode memory is present


  • To Low: press and hold from off
  • To Turbo: double click (from off or on)
  • To Strobe: triple click (from off or on)

Low voltage warning:

  • When the voltage gets low, the LEDs under the button will begin to blink red 


  • Strobe is accessed by a triple click

Lock-out mode: 

  • It has a lockout mode, click 10 times to lock it out, 10 times to exit the lockout


  • There is no PWM in any mode, verified with a photodiode

Additional info on the UI: 

  • The Convoy store listing mentions low voltage protection (“LVP”) and temperature control protection. I’ve verified the LVP, but I’m not entirely sure about temperature control protection. Read more in the Performance section.
  • Based on Tom E’s teardown at BLF, we can see that the driver is built around linear-regulator circuitry, using an op-amp, RC filters, and large FETs and current sense resistors. This driver style provides some benefits such as constant current and no PWM. Unfortunately, though, it also means that any “excess” voltage (battery voltage being higher than the LED’s forward voltage) gets burned off as waste heat.
  • Thankfully the store listings for the 3x21A include instructions for the UI, since no manual was included in the box. I don’t need a full manual, but a small instruction sheet in the box would have been nice.

Batteries & Charging

The Convoy 3x21A handles 3x 21700 batteries. While it is designed to accommodate button-top batteries, it comes with an adapter plate that allows you to use flat-top batteries. If you have raised-top batteries, you can just leave out the adapter plate.  All three batteries are in parallel, so in theory, you could use just one battery if you had to but I wouldn’t recommend it.

The flashlight has built-in USB-C charging, spec’ed at 3 amps. One of my biggest questions in these situations is whether it handles USB Power Deliver (“PD”), that is: USB-C to USB-C charging. I’m excited to report that it does! While charging with a USB-PD charger, I’ve seen a 12.6 watt charge rate (2.52 amps at 5.02 volts). Dividing that 12.6 watts by 4.2 volts (approx charge voltage) gives 3 amps, confirming the charge spec. A full charge cycle of 3x 5000 mAh batteries (Samsung 50G) took 6 hours and 7 minutes. While the batteries were charging, the LEDs in the button glowed red (I think) and then changed to green when charging was complete. Overall, this is a pretty good charge rate for built-in charging and is very convenient. However, if you have a nice 3+ bay charger available, you can charge the batteries much faster that way. My Vapcell S4 Plus could charge the batteries in 2 hours.


For current measurements, an ANENG AN8008 multimeter and UNI-T UT210E clamp meter were used. Lux was measured by a UNI-T UT383 BT at 10 meters. Lumens were measured in a homemade lumen tube using a TSL2591 sensor, calibrated with a Maukka calibration light. Testing was performed with three Samsung 50G batteries.

Parasitic drain:

  • 33 uA, nice and low!

Runtime graph

When I first turned the Convoy 3x21A on in Turbo, it hit 5729 lumens before it started sagging with the battery voltage. By 30 seconds it was at 5489 lumens. A ramp-down kicked in at 1 minute 20 seconds, dropping down to 2482 lumens over the next minute. The output stayed in that ballpark until 2 hours and 5 minutes when low voltage protection kicked in. It continued to chug along at 70 lumens until 7 hours and 32 minutes. While a ramp-down occurred, the level to which it decreased was still high enough to produce considerable heat. Against my better judgement, I let the runtime test continue and the light eventually topped out at a worrisome 81.6°C. Way too hot for my level of comfort, and probably way too hot for the batteries. I do not recommend letting this light sit in Turbo/High unless you have good air movement!

Out of curiosity, I performed another runtime test in Turbo, but this time with a fan pointing at it. This served well to keep the light cool and out of the danger zone. Most of the test performed the same, except when it got to 1 hour and 17 minutes, the output actually began to climb back up. It eventually hit 3619 lumens before output started going back down. I’m not quite sure what to make of this test, except perhaps the temperature regulation decided to let the output increase again. Either way, with a breeze blowing across the light, the highest temperature I observed in this test was a much safer 42.6°C.

The High output tests were very similar to the Turbo tests except for the first 2 ½ minutes. The High test started out at 2374 and dropped to 2311 by 30 seconds. Output stayed fairly flat, but by 1 hour and 13 minutes the heat climbed to an uncomfortably hot 75°C and I terminated the test. I charged the batteries up and re-ran the test using a fan for cooling. The output was similar, but the 3x21A stayed comfortably cool. Low voltage caused the output to drop at 2 hours and 21 minutes to 72 lumens.

Lumen measurements

ModeAmpsSpecs10min30 secstart
Moon82 mA3536
Low160 mA6972
Med1.95 A844875
High5.6 A226523112374
Turbo15.1 A6800*24145489 lm5729

* One thing worth noting is that Convoy specifies that the 6800 lumens claims is a “theoretical LED output value, the actual light output is lossy, for reference only”. I measured a bit lower than that, partially due to the fact that I chose 5000K instead of 6500K. Lower CCT LEDs almost always have lower output.

Throw numbers: 

  • Spec, SFT40: 265,000 cd / 1029 meters
  • Spec, SST40: 142,500 cd / 755 meters
  • Measured, SST40 @ 0 sec: 138,800 cd / 745 meters / 815 yards
  • Measured, SST40 @ 30 sec: 128,800 cd / 718 meters / 785 yards


The farm shed in these beamshots is 100 meters (109 yards) away. Pictures were taken with my Pixel 3 using ƒ/1.8, ⅕ second exposure time, ISO200, and 5000K white balance

  • Convoy 3x21A
  • Convoy L7
  • Convoy M21D
  • Mateminco MT90Mini SBT90.2
  • Fenix LR50R

Disclaimer: This flashlight was sent to me for review at no cost by Convoy. I have not been paid to review, nor have I been holding back on problems or defects.

Final Verdict


  1. Built like a tank
  2. Decent UI with shortcuts
  3. Bright & throwy
  4. Built-in 3 amp charging
  5. USB-PD compatible


  1. Questionable temperature regulation
  2. Ramping levels need adjustment

Explanation on star ratings:

1: Avoid: my phone flashlight would be a better choice – 2: Poor: significant defect or issues, much better options available at the same price – 3: Average: some defects or issues – 4: Good: recommended (minor issues) – 5: Great: highly recommended

Reviewer Gabriel
Author: Gabriel

4.5 stars: ★★★★⋆

The Convoy 3x21A is a beast of a flashlight. You get Convoy’s solid build quality and plenty of power to create a solid wall of light that reaches a good distance, and that’s with the fairly floody SST40 LEDs. When equipped with the brand-spanking-new SFT40 LEDs, the beam intensity is said to nearly double!

The light did arrive with smooth ramping mode enabled by default, which could use some work.  Thankfully, switching to stepped mode is easy and provides a much more logical brightness progression. Also, the 3x21A supposedly has temperature regulation, but I experienced dangerously high temperatures when left unattended with no air movement.

All in all, I am really pleased with this new model though. It accepts high-capacity 21700 batteries, has 3-amp USB-C charging that is Power Delivery compatible and has a pretty good UI. I appreciate the choice of smooth and stepped modes, as well the shortcuts for “moonlight” (not really a moonlight with a light this powerful) and Turbo. If you’re in the market for a robust, super-bright light that doesn’t break the bank, the Convoy 3x21A is worth a look!

Convoy 3x21A for sale

1lumen selects and reviews products personally. We may earn affiliate commissions through our links, which help support our testing.