Convoy M3-C

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Convoy M3-C Specifications

Brand/model	Convoy M3-C
LED	Cree XHP70.2 (4000K)
Lumens	Unspecified (previous version was 4300 lm)
Beam intensity	N/A
Battery config.	1*26650 / 1*18650
Material	Aluminum
Modes	5 and ramping
Blinkies	Strobe, battery check
Reflector	Orange Peel
Waterproof	N/A
Review date	January 2021

Another Convoy light! We sure do like reviewing these. Convoy is well known amongst flashlight enthusiasts. Especially for their low cost and easy to mod S2 and C8. Convoy also sells the hosts to many of these lights by themselves, so they’re well-liked by people who like modding lights.

In the past, they’ve mostly had physical tail switches but over the past year or so Convoy has started to introduce new hosts with e-switches. They’ve also been busy building lights with recent LEDs. Simon at Convoy is well known for selling you almost any host/driver/LED combo you can imagine.

This review is for Convoy’s M3-C. It’s a new e-switch light, with the CREE XHP70.2 LED taking 26650 cells. This sits alongside their Convoy 4x18A (4*18650) and Convoy M21C-U (21700), which we’ve reviewed before and have the same LED and similar UIs.

The M3-C is an updated version of the Convoy M3. This one includes USB-C charging and the UI has ramping, like the M21C-U.

Convoy offers the XHP70.2 in CCTs from 3000K to 6500K. I went for a warm white 4000K, which is subjectively nicer but will have slightly lower specs than the 5000K and 6500K.

Package quality.

The M3-C came in a solid brown cardboard box with a label with the model and foam insert. The box does its job fine – Convoy doesn’t waste money on fancy packaging. 

Inside the box I found:

• Convoy M3-C flashlight
• 2 rubber rings to be used as a cell adaptor
• A couple of extra springs (maybe these were intended for someone else?)

No manual (a basic manual is on the Convoy store listing), warranty card, lanyard, spare O-rings, USB cable, cell or anything you might expect from other manufacturers. This is fine with me (I have enough so many flashlight spares that I may start my own shop) but if you’re new to flashlights or want a fancy gift then make sure you know what you’re in for.

The M3-C looks and feels like a flashlight should do: nicely heavy and just the right size for a hand. Easy to grip but not too rough. Almost the Goldilocks of flashlights.

The side e-switch is easy to reach and doesn’t protrude too much. It’s white so it stands out but it’s not lit. It’s not as difficult to find in the dark as some e-switch lights but not as easy as a rear switch or some e-switches with a smaller diameter.

The USB-C cover on the other side makes a good seal, giving a satisfying little “pop” when opened. It’s very easy to knock open due to the little tag at the bottom though, so not quite perfect.

Being a 26650-cell light it won’t fit in jeans pockets but should be fine in a jacket. It can tail stand, head stand, and sits still comfortably on its side due to the indentations on the head and tail.

Whilst there’s no lanyard in the box, there’s 2 fairly hefty holes for one, so a heavy-duty lanyard can be attached without compromising the tail standing ability.

The M3-C has Convoy’s matte black anodising on the aluminum to give it a very slightly rough texture.

There’s knurling if you can call it that, but it isn’t really like knurling on most flashlights. Instead of 1mm sized bumps the body tube is covered in lots of 3mm by 5mm rectangles. These provide good grip.

Both sets of threads on the body tube are square cut, with the ones on the tail being anodised to allow locking out the light with a quarter twist.

Inside the tail there’s the brass spring. There’s no spring bypass in this one, but it would be easy to mod as the retaining ring comes out easily. The driver end has a brass pillar rather than a spring.

I haven’t managed to remove the retaining ring holding the driver in place yet but the driver looks to be 26mm. 

As far as warranty goes, Convoy doesn’t seem to have anything official but generally, if a flashlight is broken then they’ll send you replacement parts.

The M3-C comes with a domed CREE XHP70.2 sitting on a 20mm MCPCB. This one has a warm white 4000K CCT emitter but the flashlight is available in anything from 3000K to 6500K. Convoy doesn’t state what bins the different emitters are.

Also check out some of our recommended CREE Flashlights here.

The bezel is crenelated so you can see if you left it on when upside down. If you unscrew the bezel (the same matte black aluminum as the rest of the light) you’ll get easy access to the insides. An anti-reflective glass lens sits behind an O-ring. Remove that and you get to the 30mm deep reflector.

Unfortunately, the 4000K has a fair bit of tint shift between hotspot and spill. The orange peel reflector alleviates this a bit but it’s still very noticeable. Aside from the tint shift, the beam profile is very good and doesn’t suffer from rings or donuts. The large XHP70.2 LED makes the light more of a general-purpose light than an especially throwy one. 

The M3-C has a boost driver to step up the 3.7V from the cell to the 6V or 12V the emitter needs. The means you’ll see nice flat lines on the run time charts (if you haven’t already skipped ahead).

• Length: 14.91cm / 5.87 inches
• Head diameter: 4.80cm / 1.89 inches
• Body diameter: 3.54cm / 1.39 inches

Weight: 

• With a 26650 cell: 371g / 13.1oz
• Without cell: 281g / 9.91oz

Size comparison

Compared to other popular flashlights.

From left to right: Convoy M3-C (26650), Sofirn SP36 (3*18650), Astrolux FT03 (26650), Nightwatch NSX3 (21700), Convoy Z1 (21700).

Convoy are known for their mechanical tail switches and not their e-switches, so it’s nice to see a Convoy with a side e-switch. The interface works OK but after using the light for a bit, there are a few things that don’t quite work as well as I’m used to with flashlights with Anduril. I’m not talking about Anduril’s special features light lightning mode here, more the user experience niggles that make you realise why Anduril feels right. I’m a fan of e-switches, so Convoy is going in the right direction here but I hope they make a few improvements in future firmware. I have lots of opinions about user interfaces, so apologies for the essay!

The M3-C has moonlight (0.2%) and you can configure the light to do either stepped ramping (1%, 10%, 40%, 100%) or gradual ramping (1% to 100%).

Having the choice is very welcome here. Although I normally like ramping in a flashlight UI, I’ve left the M3-C on stepped modes as it’s quicker and more predictable than ramping mode.

From either configuration:

From off:

• Click for on (mode memory)
• Hold for moonlight
• 3 clicks for strobe (100%)

Special modes (only from off):

• 4 clicks for tactical mode
• 5 clicks for battery check (blinks cell volts and tenths of volts)
• 6 clicks to switch between ramping and stepped modes
• 10 clicks for lockout (blinks when clicked or held, stays locked out when power disconnected)

From on (normal modes):

• Click for off
• Hold to ramp or change modes
• Double click for turbo

If you unscrew the tail cap whilst it’s on and screw it back on then the light will come back on the same level as before. This UI would probably work with a dual e-switch + mechanical switch combo.

From moonlight:

• Click for off
• Double click for turbo

Moonlight is a bit weird. Note that holding from moonlight doesn’t do anything in either ramping or stepped modes. Moonlight mode isn’t saved in mode memory. Disconnecting power whilst on moonlight and reconnecting power doesn’t turn the light back on.

From strobe:

• Click for off
• Double click for turbo

From tactical mode:

• Hold for on (100%)
• 4 clicks to off

The light is off in tactical mode. A quick click does nothing.

Ramping:

• Hold to ramp up or down, depending on what you did last

The light will blink to signify you’ve hit the ramp floor (1%) or ceiling (100%). This is useful but blink is on the sluggish side. You can’t ramp all the way down to the 0.2% moonlight, only the 1% ramp floor.

There’s “direction memory” on the M3-C. That means that if you last ramped up 5 minutes ago then next time it will ramp down and vice versa. It even remembers the direction after being off (but not after cutting power). Another niggle with this: if you last ramped down then double click for turbo then hold the button, the light will think it’s meant to be ramping up from turbo and will do nothing other than blink to signify it’s at 100%.

Ramping is linear over the whole range and takes about 3 seconds. As our eyes perceive light exponentially, this makes the top of the ramp seem slow and the bottom of the ramp seem quick. An exponential ramp would be a nice improvement here.

Another thing I miss from Anduril is the option to “tap and hold” to change ramp direction. On the Convoy, tap and hold does exactly the same as just hold, ignoring the first tap.

Stepped modes:

• Hold to ramp up

Stepped modes are exactly what you’d expect. They always go up: low, medium, high, turbo, then back to low. Or as Convoy call them: 1%, 10%, 40%, 100%, then back to 1%. These are spaced quite nicely and the 4 levels plus moonlight seems to be enough for a light like this – but remember that you can’t cycle to or from moonlight without turning the light off. The 40% is almost exactly what the light can sustain at room temperature.

PWM

With a camera it seems I could just detect a little PWM on low and medium. This is barely noticeable, even with a camera, so don’t think it’s anything to worry about.

Cell compatibility

The Convoy M3-C didn’t come with a cell but it looks like Convoy is now giving the option of a 26650 cell along with the light. Convoy recommends 11A+ 26650 or 18650 cells are used for best performance.

The light is sized for 26650 cells. I had a 5000mAh LiitoKala on hand but the best option right now is probably the 15A 5500mAh Keepower cell. The cell I had is 26.1mm in diameter and rattles a little in the 27.22mm inner diameter of the M3-C. This can be fixed with a bit of plastic. Convoy also includes 2 rubber rings that fit around an 18650 cell perfectly, making them fit perfectly in the M3-C. Convoy doesn’t mention 21700 cells on the product listing but they fit fine in the light with a bit of plastic as a homemade spacer.

Charging

The main upgrade of the M3-C over the original M3 is probably the USB-C charging port. This is opposite the switch and includes a recessed red/green indicator light.

Charging started off at 1.83A with the red indicator light on. The current slows to a trickle then the indicator turns green and stops charging. The M3-C charged cells up to 4.18V.

Lumen measurements:

Lux meter: All lux and lumen measurements are from my home made integrating sphere, calibrated with a range of factory specced lights. Measurements are done with a UNI-T UT383S lux meter and Adafruit TSL2591 connected to a Raspberry Pi (using RuTiTe by bmengineer). Expect them to be within +/-10%.

DMM: Current readings were taken with a Precision Gold PG10B DMM, all with the cell charged to 4.20V.

Cell: used a 26650 LiitoKala 5000mAh for the measurements, charged up to 4.18V.

Amp measurement  

• 1%: 0.06A
• 10%: 0.66A
• 40%: 2.19A
• 100%: 9.23A (at 0 seconds)

Runtime graph

Starting off at the highest mode (100%), the M3-C hits 4374 lm at 0s and 4235 lm at 30s. After 4 minutes it starts dropping and at 10 minutes it’s down to about 1800 lm. Another 10 minutes and it’s only dropped to 1600lm, which it holds without faltering for an hour and a half. Here the low voltage protection starts to kick in and drops the light down to 1%, with an intermittent flash to warn you the cell is running out. The M3-C finally turns off when the cell is at 2.92V.

From 21℃ room temperature, the flashlight gets up to 45℃, which it maintains the whole time. This isn’t too hot at all and would be safe for kids.

On the second-highest level (40%), the light starts off at 1524 lm and barely drops 100lm over 2 hours and 20 minutes. The driver does a great job of getting the same current to the LED even as the cell voltage drops.

The driver and XHP70.2 LED have very good efficiency, allowing the M3-C to get well over 2 hours of over 1500 lm from a 5000mAh cell.

Lumen measurements (for each mode)

Mode	0s	30s
1% (low)	37 lm	37 lm
10% (medium)	519 lm	519 lm
40% (high)	1524 lm	1516 lm
100% (turbo)	4374 lm	4235 lm

Throw numbers: 

Throw measured at 5m:

Mode	Candela	Throw
1% (low)	266 cd	33m
10% (medium)	3957 cd	126m
40% (high)	11.5k cd	215m
100% (turbo)	33.4k cd	365m

The M3-C has a good even beam at around 7.6cd/lm, making it a bit more throwy per lumen than the Sofirn SP36 but not quite as throwy as a BLF Q8.

Distance to the far building is 55m. Photos were taken with a Pixel 3a, set to 1/2s shutter speed and ISO 400, F1.8. 

• Astrolux FT03
• Convoy M3-C
• Convoy Z1
• Convoy Z1
• Emisar D4
• Nightwatch NSX3
• Sofirn SD05
• Sofirn SP36

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.