Convoy 3X21C Review – UI Letdown

1. Pricing & Availability
2. What comes in the box?
3. Design & Construction
4. Size & Measurements
5. User Interface
6. Emitter & Beam
7. Mode Chart
8. Runtime
9. Driver & Regulation
10. Batteries & Charging
11. Switch
12. Carry & Ergonomics
13. Competition
14. Conclusion

Pricing & Availability

Convoy sent me this light in exchange for an honest review. Here is the official product page where you can see current pricing. At the time of writing, it’s $89 USD with the optional Molicel P45B batteries I chose.

What comes in the box?

The box is basic brown cardboard with a nice foam insert and a tiny sticker stating the contents. Inside is:

• The light itself
• Batteries (optional)
• Flat top battery adapter
• Handle & thumbscrew

The manual is not included in the box, so you’ll have to refer to the product page for that information.

Design & Construction

The design is great. I think the flared head makes it look smart in a way that most soda can lights don’t. I love the shape and looks of this host.

Build quality is excellent. It’s better than the price would suggest. What most impressed me was how the tail contacts are constructed. Instead of a simple PCB with springs soldered to it, 3X21C has a machined block of aluminum in the tail with three threaded brass retaining rings holding down thick springs.

My only complaints about build quality are that one of the screws holding down that aluminum block was stripped from the factory, and the handle is a bit wobbly.

Size & Measurements

Olight Warrior 3S | Maglite 2D | Convoy 3X21C | Convoy 3X21D | Mini Maglite

Measurement	Measured (mm)
Bezel Diameter	74.0
Length	148.0
Switch Diameter	~10.5
Body Tube Diameter	50.4
Tailcap Diameter	53.5
Tailcap Length	13.3
Driver Diameter	40
Weight with P45B batteries	695

User Interface

This UI lacks critical features and that makes it consistently annoying to use. It’s a real shame, and largely ruins the light for me. Note: Since posting this review, 3X21C has been updated to have a Buck+FET driver which has some UI changes that are not reflected in this review.

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.

State	Action	Result
Off	1C	On
Off	4C	Momentary
Off	5C	Voltage
Off	10C	Lockout
On	1H	Adjust brightness (Low-Med-High-Turbo, or smooth ramping)
Any	2C	Turbo
Any	3C	Strobe
Any	6C	Toggle stepped/smooth ramping
Turbo	2C	Return to previous level
Momentary	4C	Off
Lockout	10C	Off (unlocked)

Basic E-switch UI Checklist: 7/12

• 1C on/off✅
• 1H to change brightness✅
• Stepped levels✅
• Main rotation is Low-Med-High❌
  • Main rotation also includes Turbo
• Moonlight shortcut: 1H from off❌
  • There’s no Moonlight (no big deal on this light) and there’s no shortcut to the lowest mode at all (that’s a big problem). You can loosen the head and re-tighten it to reset the mode memory to low, but that’s slow and requires two hands.
• Low shortcut: 1H from Moonlight❌
  • There is no Moonlight mode, nor a shortcut to Low.
• Turbo shortcut: 2C from anywhere✅
• Strobe shortcut: 3C from anywhere✅
• Mode memory for Low, Medium, and High✅
• No mode memory for Moonlight, Turbo, and Strobe❌
  • Turbo is memorized, even when accessed by shortcut.
• 4C to lock/unlock❌
  • 4C enters/exits momentary mode. 10C enters/exits lockout mode, which is excessive.
• Does something when you click the switch in Lockout mode✅

Notes:

• The UI seems to depend on the driver. My 3X21D with the available Buck has a similar UI but it adds a Moonlight mode and a shortcut to it.
• Hold is slow. The mode cycle when holding is very slow. It’s actually faster to to repeatedly do a short hold and release and hold again to cycle to the next mode.
• Momentary mode should require a power cycle to exit. As is, you could accidentally exit just by clicking 4x.
• The voltage readout and smooth ramping option are nice features that most companies don’t bother include.
• 2C from Turbo jumps back to the memorized mode. That’s handy, especially because there’s no shortcut to the lowest mode from off.

Emitter & Beam

3X21C is available with two LEDs (Luminus SST40 and SFT40) in two color temperatures (5000K and 6500K). I chose SST40 6500K LEDs for the widest beam and most brightness.

The beam is surprisingly balanced. I expected it to be a lot floodier. Choosing SFT40 LEDs will make it throwier. There are six flower petals surrounding the spill, resulting from the compound reflector with overlapping cones.

In the beamshots below, the fence is 16 meters away and the fountain is 86 meters away.

In the beamshots below, camera settings are fixed and the wall is 2.8M away.

In the beamshots below, camera settings are fixed, the basketball goal to the right of the hotspot is 39M away, and the power pole in the center is 185M away.

Mode Chart

Disclaimer: All of my measurements are taken at turn-on. 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 III on the highest brightness, and other candela figures were calculated relative to that. CRI, CCT, & DUV data were 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. 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 these measurements with a grain of salt.

The official specs on the product page state up to 15,000 lumens, but Convoy tends to advertise theoretical LED output not the actual out-the-front measurement. The 12,000lm I measured is about right if it’s theoretically making 15,000 at the LEDs.

My measurements:

Level	Lumens	Candela	Throw (Meters)	CRI (Ra)	Color Temp. (K)	DUV (Tint)
Turbo	12000	210000	917	65	7252	0.0076
High	3200	56000	473	66	7400	0.0063
Medium	1100	19250	277	70	6960	0.0007
Low	160	2800	106	69	6700	0.0023

Runtime

Performance: Sustained output without any cooling is north of 1000lm, which is about what I’d expect from a FET driven light this size. That’s significantly worse than lights this size with better quality drivers, but those are usually much more expensive. Brightness trends downward on Medium and Low as the battery drains, which is typical of FET drivers. Note: Since posting this review, 3X21C has been updated to have a Buck+FET driver which should improve runtime and regulation performance in every mode except Turbo.

Thermal regulation: My Turbo, Turbo Cooled, and High tests are all markedly different, so there is active thermal regulation. It only seems to kick in after the initial timed stepdown though. My Turbo test had a fan circulating air in the room, while the Turbo Cooled test had the fan pointed directly at the light.

LVP (Low Voltage Protection) is present according to the product page. This light runs for a long time at low output when the batteries get low and I ended all my tests before it fully shut off.

Driver & Regulation

The driver is 54A FET. FET drivers provide a ton of current at a low price, but poor efficiency and regulation performance. Convoy’s 25A Buck driver is also listed in the product description so it may be an option for 3X21C. That driver will provide lower Turbo brightness but offers better efficiency, a bit better UI, and a powerbank function. If you really want a 3X21C, I recommend requesting the Buck driver. Note: Since posting this review, 3X21C has been updated to have a Buck+FET driver which should improve runtime and regulation performance in every mode except Turbo.

Regulation performance is below average. That’s to be expected from a FET driver like this. Every mode is affected by battery voltage, but you probably won’t notice until the battery is virtually empty. Note: Since posting this review, 3X21C has been updated to have a Buck+FET driver which should improve runtime and regulation performance in every mode except Turbo.

PWM: No PWM is visible to my eyes or camera, nor audible to my ears. That struck me as unusual for a FET light so I also tested with my Opple. It was able to detect some sort of digital flickering on the lower 3 modes, but all at 32khz (well outside human hearing range). Nicely done, Convoy.

Parasitic Drain: 32 microamps. That will take ~50 years to drain the Molicel P45B cells included with my sample.

Batteries & Charging

The batteries are optionally included, and Convoy offers several to choose from. I chose Molical P45Bs for their high drain and relatively high capacity. They do a great job here. A spacer is included for using flat-top cells. Any unprotected 21700 cell should fit, button or flat-topped. Be careful not to insert any of them backwards as that risks creating a dangerous short circuit. That’s why most competitors require button-top cells, to avoid short circuits.

Charging is facilitated by a USB-C port under a silicone cover on the side of the head. Charging takes 4.5-5 hours. There is no powerbank function, which is a shame. That’s an expected feature on a light this size with a charging port. The buck driver mention on the product page has powerbank functionality, but I don’t know if you can get it in this light. The light is fully functional while charging. If you plug it in without batteries, it’ll work, but the mode spacing is weird and it doesn’t get as bright.

The battery indicator LEDs are located under the switch and they only come on during charging. Red means charging and green means fully charged. I wish they also activated for a few seconds when you turn the light on.

Switch

3X21C has an electronic side switch with a grey silicone boot. It’s clicky and tactile, but it can take a moment to find in the dark. There are LEDs under the switch to indicate charging status. I like side switches on large lights because they’re easy to access in most grips and provide full control over the light with one hand.

Carry & Ergonomics

Ergonomics are good. It’s comfortable to hold and in a forward or neck grip. My only complaint is the milling on the body tube isn’t as grippy as I would like (nor as grippy as my 3X21D tube). It works well in a forward grip with my thumb on the button or in a neck grip with my middle finger on the button.

A handle is also included and leaves some things to be desired. The screw holding it on is very difficult to tighten by hand, and there’s no way to use a screwdriver. You can’t reach the switch when holding the light by the handle, so you need two hands to operate it. The mounting holes are threaded like tripod mounts, but their positioning beside the wider head makes tripod mounting nearly impossible. On my sample, the handle wobbles a bit on one side and wobbles a LOT on the other side. I think the thumbscrew might back out after awhile.

Competition

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

Sofirn Q8 Plus: mostly better alternative

• similar price with batteries
• similar driver quality
• more brightness, less throw
• less attractive design
• powerbank function
• feature rich but complicated Anduril firmware
• six XHP50.2 LEDs
• lower build quality (not bad though)
• no handle included
• no flat-top battery adapter
• can be mounted to a tripod
• more easily available, and with fast shipping

Convoy 3X21E: floodier, high-CRI alternative

• similar price
• similar brightness, much floodier, less throw
• same driver with bad UI
• grippier body tube
• twelve Nichia 519A LEDs under TIR optics
• shorter and narrower head

Noctigon M44: enthusiast alternative

• more expensive
• better quality driver
• Less brightness and throw
• wide range of LED options
• Dual-channels (selectable and mixable colors)
• Uses three 18650 batteries (not included)
• No integrated charging
• RGB auxiliary LEDs
• Sixteen main LEDs behind swappable TIR optics
• Feature packed but complicated Anduril firmware

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

I love the design, build quality, and brightness. I like the beam, charging solution, and ergonomics. I dislike the regulation performance (though it comes with the territory) and missing powerbank function. I strongly dislike the UI, which makes 3X21C difficult to recommend.

Thanks to Convoy for sending me this light for review!