Convoy M2 Review

This content originally appeared on Reddit on May 29th, 2021.

The Boring Stuff

This light was kindly sent to me to by u/eckyeckypikang! Please accept this digital shrubbery as thanks! 🌿🌳🌿

The light is available for purchase on the official product page on Convoy’s Aliexpress storefront. There are several other emitter options available as well. Below are the official specifications.

What Comes in the Box?

The box is a basic, thin, white, cardboard box with just enough room. Inside is the light itself, wrapped in a bubblewrap sleeve, and a very simple lanyard. The box has a plain sticker on the side denoting the model and emitter selection. Convoy wasted no money here and the packaging does seem pretty flimsy. I think I would rather have seen one of their nice, brown, carboard boxes with foam insert used here.

The light was already a little scratched up from a drop before it was sent to me, so I can’t tell how well this packaging protected it during shipping.

Size Comparison

Measurement	Official (mm)	Measured (mm)
Head/Bezel Diameter	31.6	31.6
Bezel Inside Diameter	not specified	26.5
Body Diameter	25.8	25.5
Clip Slot Width	not specified	7
Clip Slot Diameter	not specified	22.8
Lens Diameter	29	29
Lens Thickness	1.6	1.6
Reflector Max Diameter	28.9	28.9
Reflector Hole Diameter	7	7
Body Tube Inside Diameter	not specified	19
Tailcap Diameter	27.5	26.3

The official measurements were taken from the product pages of the light, its lens, and its reflector.

User Interface

The 5A driver used in this light has Convoy’s “12 Mode Group” firmware installed on it. It’s very similar to Toykeeper’s “Biscotti” firmware Convoy has used in the past. It gives you 12 different mode groups to choose from and allows you to enable or disable mode memory.

State	Action	Result
off	half-press	no action
off	click	on (mode memory optional)
on	half-press	next mode in group
on	click	off
on	20+ half presses	configuration mode

Changing mode groups or the state of mode memory is a little too complicated to get into here, but it’s not hard to figure out and becomes second nature once you’ve done it a couple of times. Check out the official product page if you want more info. I find I like mode group 4 with no memory the best. It goes 1%-20%-100%-strobe-bike flasher-battery check-SOS.

This is one of the better firmwares available for mechanical switch lights, though I do think it has a lot of room for improvement. The two biggest changes I want are a much lower lowest mode and a double-tap shortcut to 100% mode. Below you can see how much brighter the M2’s lowest mode is compared to the D4V2, M1 H17Fx, and KR1 which all have a lowest mode of about 1 lumen or less.

One peculiar thing I noticed about this light that differed from my other Convoy’s is that the light never stops turning on when you try to enter config mode. It continues to turn on in the lowest mode every time. This isn’t an issue, it’s just different than the directions indicate and different than the other two Convoy lights I’ve tried.

Regulation

Battery Voltage	Measured Relative Output	Lumens (*Estimated)
4.20V	100%	~900
3.71V	105%	~941
3.46V	73%	~660
3.20V	71%	~643
2.95V	28%	~248

* The lumen data above is based on the assumption that this light has a peak output of 900 lumens on the 100% mode and with a fresh battery. The rest of the lumen numbers are simply calculations based on the relative output. These tests were done using the ceiling bounce app on my smartphone so take them with a grain of salt. Unless otherwise specified, all tests were performed with a fully charged Samsung 30Q cell.

Overall regulation is good. The light can produce over 70% of it’s maximum output all the way down to 3.2V (and possibly lower). The runtime graphs are also very flat as you’ll see in the next section.

Runtime

* The lumen data above is based on the assumption that this light has a peak output of 900 lumens on the 100% mode and with a fresh battery. The rest of the lumen numbers are simply calculations based on the relative output. These tests were done using the ceiling bounce app on my smartphone so take them with a grain of salt. Unless otherwise specified, all tests were performed with a fully charged Samsung 30Q cell.

100%: Starts to step down fairly quickly and settles at ~550 lumens just after 3 minutes. That output is held perfectly stable until ~75 minutes when a slow stepped decline begins. There are a few low voltage warnings, ending in low voltage cutoff a little over the two hour mark. End voltage was 2.95V.

35%: Looks largely the same as 100%, minus the first few minutes of increased brightness. I’m not certain why there is a brightness drop at ~10 minutes. It could just be a fluke in my testing.

20%: A perfectly flat ~375 lumens until the slow brightness drop begins at 143 minutes. Low voltage protection (LVP) shuts the light off at 190 minutes.

10%: A perfectly flat ~215 lumens until the slow brightness drop begins at 291 minutes. Low voltage protection (LVP) shuts the light off at 351 minutes.

Runtimes are perfectly reasonable. Sustained output is also remarkable high compared to the Noctigon KR1 with the same emitter.

Emitter & Beam

This particular variant of the M2 uses an Osram KW CSLNM1.TG emitter, also known as the “W1”, on a 20mm copper MCPCB. At the time of writing it’s the highest intensity (lux per die area) emitter on the market. As a result it provides some excellent throw performance. As you would expect, this light has a remarkably throwy beam for its size.

The green electrical box in the hotspot is ~90ft (~27m) away

The garage door is ~25ft (7.5m) away

The treeline is ~1900ft (~579m) away

See the more beamshots in full resolution here.

The M2 has a remarkably throwy beam. The hotspot is similar to the Noctigon KR1, just not quite as defined. Overall the hotspot and emitter centering are satisfactory.

The spill, on the other hand, is not. There’s a big, bright, ugly ring. Initially I thought this was caused by the stainless bezel, but it’s present without the bezel installed and with the inside of the bezel covered in black tape. This makes me think it’s actually a design flaw in the reflector. After studying the emitter’s reflection pattern in the reflector, I see a small area near the base of the reflector where the reflection pattern is different. I can’t get a photo where it’s visible, but I believe this is where the big ring comes from. There is also some smaller ringing that seems to change every time I remove & re-insert the reflector so it’s possible that could be eliminated with enough trial and error. I can’t quite figure out where it’s coming from though. I also tried adding some tape to the back of the centering ring to see if I could eliminate the big ring but it had no effect either.

The deep stainless steel bezel has a couple of minor effects on the beam. First, it makes the spill fairly narrow. It’s still perfectly usable, but it’s significantly narrower than the KR1. Secondly, the crenulations are in the path of the spill, so they make the edge of the spill a bit hexagonal. These issues aren’t present on the M2’s brother, the M1.

Build

The light was damaged before it was sent to me. Please ignore the scratches seen on the head & bezel, as they are the result of a drop before the light was sent to me.

Overall this is a well built light. The machining and anodizing quality is great, as I’ve come to expect from Convoy. However, there are some issues with the design of the components in the head.

The head has an attractive design with plenty of cooling fins, which are important because it heats up quickly. Something in the head rattles a bit but I can’t quite pinpoint what it is. This head has an interesting design quirk. It has one less O-ring than most flashlights. Typically, two O-rings are needed at the bezel of a light to create a seal. There’s one that resides between the bezel and the head, and another that resides between the bezel and the glass lens. With the M2, the reflector is chamfered at the front end. This pushes the o-ring forward into the glass lens and outward into the inside of the head, creating both of the necessary seals with a single O-ring. Very cool!

Unfortunately, I think the O-ring Convoy used here isn’t quite thick enough. Something rattles in the head when I shake the light and that shouldn’t happen if everything is held tight. I believe the O-ring is too small, causing it not to create a seal and not to hold the parts in place firmly. I also believe the reflector isn’t quite shaped correctly, as discussed in the emitter and beam section.

The bezel is nicely machined out of stainless steel and threads into the head easily. The crenulations are a little bit sharper than those on the M1. I would expect these to wear a hole in your pocket after awhile. They do let light escape if the light is turned on bezel down on a surface, so you’re not likely to leave it on by accident. The crenulations do affect the spill, as discussed in the Emitter & Beam section.

The body tube is fairly plain, lacking any knurling. It has two flats milled in on either side where “Convoy M2” is screen printed. It also has four grooves milled in for style. The anodizing provides some grip, but not as much as the knurling on the M1. I think the lack of knurling helps distinguish this light from the M1 though, and I think it was a good design decision. It also makes the clip less likely to eat at your pocket. The body tube is not reversible because the threads on either end are not the same diameter. The threads are anodized on both ends which is somewhat unusual for Convoy. That means mechanical lockout works just fine from both ends.

The Tailcap shares the same basic design as the body tube. The two fins allow it to tailstand and it’s plenty stable. The two holes cut into one fin allow for installation of a crew-on clip or for the use of the included lanyard without interfering with tailstanding. The valleys between the fins allow easy thumb access to the switch while holding the light. Convoy’s ring magnet will fit on this tailcap should you be included to install it. It makes the switch a fair bit harder to access though.

Switch

The switch on this light is a little bit of a let down. I don’t particularly like reverse clickies generally. I see the appeal of being able to change modes while the light is on, but I find that I rarely do that. The vast majority of my usage is turning a light on to tthe level I need and then leaving it there until I turn it off. That’s a lot easier with a forward clicky switch.

The M2 uses one of convoy’s typical 16mm reverse clicky switches. This one feels a little mushy and it creaks a little when it’s actuating. The travel is a little shorter than I’d like, and there’s no tactile distinction between clicking “on” and clicking “off” like there is with a forward clicky, or even with Convoy’s 20mm reverse clicky.

Fortunately, the inside of the M2 tailcap is pretty much identical to the inside of the M1 tailcap, so my forward clicky switch setup from my M1 build (detailed in my review) fit just fine. You can also request a forward clicky switch when ordering the light and that’s what I recommend. It fits the design of this light a little better as an EDC tactical light.

With that said, the switch is perfectly serviceable. It’s just not great.

Carry & Ergonomics

I don’t like the clip the light came with. It carries very shallow, leaving 1.3″ of tailcap sticking up out of your pocket. It’s also extremely stiff. I tried it with my favorite tactical light clip, the Thyrm Switchback 2.0, but the tailcap was too thick to fit into the switchback. I also tried the Convoy Universal Clip and the Olight M2R clip. Convoy’s screw-on clip would also work. The M2R clip was my favorite because it held onto the light and held the light in my pocket well. The Convoy Universal clip was not as strong as the M2R clip, but it’s a lot easier to get since you can just order it with the light and I used it for most of my review for this reason. I highly recommend picking up both optional clips from Convoy and trying out all three.

The M2 is nice and comfortable to hold and use. Reverse grip and cigar grip both work just fine. Though it’s worth noting that the ears on the stock pocket clip can be a little pokey in a cigar grip if you hold it a particular way. The universal clip is more comfortable to hold in a cigar grip.

With 5 amps only pushing out 900 lumens or so, the light doe heat up fairly quickly. When thermally saturated I found it too hot to hold. I would like to be able to adjust the thermal limit in the programming mode.

Batteries & Charging

This light runs on a single 18650 cell. I did all my testing with flat top, unprotected Samsung 30Q’s. They fit fine, but they can rattle a little bit. Lining the cell tube with a layer or two of masking tape is a super easy fix to that. Protected button tops should work just fine.

There is no integrated charging on this light, which is a plus in my book. It keeps cost down and means there’s no silly rubber flap to deal with. Swapping cells is easy by removing the tailcap or head. If you do want integrated charging, there should be no problem using a cell with USB recharging built in.

Competition

Here are some lights that are similar to the M1 and how I think they compare to the M1.

Convoy M1: Similar price, driver options, and emitter options. More grip, slightly larger head, slightly more throw (with the same emitter), none of the weird head design issues. You can find my review here.

Noctigon KR1: More expensive, slightly larger head, slightly more throw (with the same emitter), similar emitter options, marginally nicer build quality, much better UI, more likely to activate in the pocket, shorter, inferior cell support (unprotected flat tops only).

Fenix PD32 V2: More expensive, marginally nicer build quality, inferior UI & cell support, fancier switch, narrower and shorter, more lumens but less throw, wider hotspot. You can find my review here.

Conclusion

This light could have been great, but it was let down by a poorly executed head design. The artifacts in the beam are pretty bad. The rattling and potential water resistance issues coming from the incorrectly sized O-ring and weird design don’t help either. All in all, it’s not a bad light, but if you’re interested, I recommend getting the Convoy M1 instead. It’s fairly similar to the M2 in, but it doesn’t have any of the strange design quirks or issues that are present on the M2.

Thanks for reading, and thanks once again to u/eckyeckypikang for sending me this light to play with and review!