[Review] Convoy M21C ( XHP70.2, 1 x 21700) - Excellent performance and regulation # Outdoor beamshots included

The flashlight was sent to me by Convoy for review.
Here's the product's link: Convoy M21C

Note: The XHP70.2 variant should become available in the upcoming days.

As with most Convoy flashlights, the M21C arrived in a simple cardboard box with a couple of replacement o-rings.



The flashlight comes in a nice dark grey anodization.



The head is very beefy and contains a lot of thick heatsinking grooves.



The M21C comes with a big, smooth reflector and a polished bezel.



This specific variant is equipped with an XHP70.2 5000K emitter.
Its centering is perfect.



The driver is held in place by a brass retainer.
This specific variant runs on Biscotti firmware, which I found very convenient.



Here's the head taken apart.
The emitter board is kept from rotating with two screws.



And there's the reflector and centering ring.



The flashlight is operated by a rear, mechanical switch.



The switch is reverse-clickie.
Thanks to the side flaps, the flashlight can tailstand.



The switch is held down by a brass retainer.
For better efficiency, its spring comes bypassed from the factory.



And here it is taken apart.



The tail threads are square-cut and anodized, which allows the flashlight to get mechanically locked out



The head's threads aren't anodized, but are equally cleanly cut.



User Interface

The Convoy M21C (w/ XPH70.2) I received runs on Biscotti firmware (other options might become available as well).
As with most of our members, I'm also a fan of the Biscotti firmware for mechanical-switch operated flashlights.

Here's a picture that demonstrates the available modes and actions.


I usually prefer mode group No.5 ( 1%, 20%, 100%) for most of my flashlights, as this mode spacing fits me perfectly.

Performance

Here's the output per each brightness level along with the respective current draw:



As seen, the maximum output is kept at around 4000Lm, which is very good for a single cell flashlight.
The best is yet to come ( have a look at the regulation section :D )

Thermal and Ouput Regulation

I've created the following graphs using my RD DPS 5020 bench power supply.
First let's take a look at the output regulation test.


What we can see

  • Turbo is fully regulated down to 3.2V
  • Medium and Low are fully regulated for the whole span of the battery.

I usually just like to list my collected facts, but in the case of the Convoy M21C, I got to admit that I'm very impressed of it being able to hold full output down to 3.2V

And here's the thermal regulation test.


What we can see in the graph:

  • Full output is sustained for 3.5 mins
  • After that, the output will slowly reduce for 8.5 mins down to 1500 lumen
  • The final step-down brightness (1500 lumen) if fully sustainable
  • The flashlight got warm during the span of the test, but never too hot to the touch (both the body and head).

Beamshots




Final words: I'm impressed by the M21C w/ XHP70.2 . Its built quality is, as with all convoys, excellent and its' UI and Performance are more than anyone could expect from such price-point.

What batteries does it/can it take?



Sorry for that, forgot to include the battery type in the title!
The M21C runs on one 21700 cell.

Why isnt there any level between 35 and 100? For example 70, when you want high output, but not all out turbo…

Wait a minute. Are you saying that this driver has an OUTPUT current of nearly 9A at 6-7V from a single cell? How did you complete your test with the power supply? How and where did you measure current? Were you driving an XHP70.2 on the output?

@JaredM

I have TnC 26650 UltraLux with MantaRay boost driver which measured with Fluke175 at the tail gives 10A. 6V XHP70 is the lased...

I’m under the assumption that this must be input current. The “regulation” on turbo is what I believe to be the driver capping the input current, so that it doesn’t burn up. The output amperage likely falls with voltage proportionally. It can be seen that medium mode has increasing current with decreasing voltage and maintains constant wattage (~5.5W) between 3.2-4.2V. This is proper regulation as far as I can tell. Output current is likely around 6A max.

Please correct me if you did in fact measure the output current. I would prefer to be wrong here because this means I found a driver I’ve been looking for.

SMO and XHP70.2 like seriously. This light needs a op reflector.

BTW the much smaller and lighter Thrunite TC20 stabilizes at 1800lm. I know those two brands are incomparable but nevertheless.

Can you measure the diameter of the driver?

I think it has something to do with the fact that the way we perceive light isn’t linear but logarithmic.
So having a level between 50% and 100% would hardly make any difference.

Keep in mind I could be totally wrong :slight_smile:

Please Simon, give us an OP reflector for this light!

Have you taken the driver out yet?

Are you going to?

I'd like to see photos of it outside the light.

The one photo of it inside the head doesn't reveal much.

What's on the top side?

I don't see it on the AE Convoy Store

@bilakos, could you clarify if you measured current into or out of the driver, please?

Hello Jared and sorry for the late reply!

Yes, I can confirm that I measured just the input current and not the output.
As you’ve mentioned in your previous replies, the driver seems to be capping the max current on turbo in order to not fry itself.

Do you have a size comparison?

This seems like a nice all around light from convoy.

8.87A from a mostly charged battery means about 33W input. Assuming 90% driver efficiency that is 30W to the LED. Looking at the xhp70.2 test (from Texas ace) it looks like maybe it’s sending about 5A to the LED at 6.16V.

For those saying they want an OP reflector, the xhp70.2 beam really looks fine from a smooth reflector so I don’t think that’s a big deal.

No apologies needed! Thank you! :slight_smile:

Is the driver a secret that you cannot post photos of other than the one of it inside the head.

The driver is the heart of the light so info about it is important for full review.

We like pictures!

FWIW the TC20 is much less throwy based on the beamshots here and the size of the reflector.

I second that.