Crelant 7G10 (MT-G2 | 4 x 18650 / 8 x CR123A) Review

Crelant's 7G10 is currently one of the few lights endowed with Cree's MT-G2 LED. While this particular emitter isn't new, its adoption for portable lighting use has only recently begun in earnest.

While it's still early to say what the impact will be, I suspect that we'll start seeing this emitter proliferate to all form factors of flashlights and even potentially CR123-size since despite its large die the fact that it can run on 3V makes it possible. For now, let's see what the 7G10 can do with it...


MFG FEATURES & SPECS
MSRP: $188USD

Specifications:
- CREE MT-G2 LED with 50 000 hours life span.
- Maximum output: 1860 lumens (ANSI FL-1 standard)
- High efficient constant current circuit and output-luminance
- Durable, custom-designed Microcontroller drive circuit
- Side switch and mode changing infinitely variable brightness
(Hidden Strobe and SOS,quickly click side switch twice).
- Working voltage: 5.4V--12V DC
- Battery Types Supported: 4 x 18650
- Runtime:High output at 3 A: 1860 lumens for 130 minutes.
Low output at 0.01A: 1 lumen max for 1000 hours
- Mil. Spec. Type III hard anodized aircraft grade 6063-T6 aluminum alloy
- Color: Black
- Ergonomic grip with anti-roll design
- Bezel: stainless steel
- High performance aluminum OP reflector with concentrated beam shot
- Waterproof: IPX-8 Standard
- Lens: Toughened & ultra-clear coated and anti-abrasive glass
- Dimensions: Length 198mm, Head Diameter 79mm ,body 54mm
- Weight: 644g excluding battery
- Accessories: Lanyard, spare o-ring

Features
- Specially designed for Military, Law Enforcement, Self-defense, Hunting,
Search& Rescue and Outdoorsman
- Side switch with infinite brightness system
- Stainless steel retaining ring on the bezel protects the head from drops and impacts.
- CREE New MT-G2 LED
- Max output of up to 1860 lumens with an effective range of 550 meters
- New hybrid reflector specially designed for CREE LED, which allows for better beam quality, efficiency and throw capability
- Newly designed high efficiency broad voltage drive circuit maintains constant
brightness and maximal runtime
- IPX-8 standard waterproof


PACKAGING / CONTENTS
The 7G10 arrived in a sturdy cardboard box w/decent foam cushioning:


Accessories included are:
Lanyard, 2 x O-Ring and as purchased from md-lightsource a GITD lanyard (attached to light):



VIDEO REVIEW
Here's a vid review of the 7G10 while I flesh out this written review:
http://www.youtube.com/embed/-fEu6JxAoIk


SIZE / HANDLING

L to R: RL3400 | L3 Illuminations K40 | Crelant 7G9 | Crelant 7G10 | ThruNite TN31


BEAMSHOTS
Here's an outdoor vid comparing the 7G10 to a few other larger lights from my collection (please see this thread for full details and distances involved):
http://www.youtube.com/embed/pGXrrpgF03w


RUNTIME & OUTPUT
The relevant battery stats are provided above each runtime graph along with:
- Voltage of the battery at the start and end of the test
- Current draw
- Actual runtime using ANSI FL1 (first in HR and then in M so for the RL3400 on High, read this as 2.6hrs or 156min)
- As of May 2012: Lumens measured on my PVC LMD @ 30 seconds
- Also captured the temperature: ambient, the head/fins at start and the max it reached (fan was used)


Max output measured @ 30 seconds was 1690lms w/4 x RediLast 3400 (note: although I calibrate my PVC LMD before each 0runtime/lumens testing, the ambient temp will also cause deviations in readings).

The 7G10 takes an immediate nose dive upon turn on and drops roughly 200lms in the first few seconds. I wasn't able to match the 1860lms claimed but wasn't too far off at 1690lms. After the drop, it does a milder decline before finally settling into a quasi-regulated mode after 10 min and runs in this state until it drops out of this "regulation" a little before 50 mins. It then starts a general decline and the LVW will briefly kick-in eventually but it's easy to miss if you so happen to not be paying attention to it. Thus it's always best to recharge the batteries ASAP whenever output decline appreciably. The cells measured ~3.09V ea (reminder that the carrier holds cells in 2S/2P config) by the time I manually stopped the run.

Given the 7G10 can run on CR123A's as well, I suppose it's a good thing that it can continue to drain the cells after the LVW kicks in but one just needs to be mindful of that when using LiIon cells.


=======
7G10 provided by md-lightsource.com for review.

The lowest voltage MTG2 part is ~6v, actual Vf is around 6.2v@3A and 6.6v@5A. That plus the low end of the input voltage range in the specs of "5.4v" explains the dropoff in output (these LEDs won't even light up at 5.4v)? Any indication this light uses a boost or buck-boost driver?

Hmmm I read the spec sheet wrong for some reason so good catch, you are right that lowest v MTG2 will run on is 6V. The immediate steep drop at turn on leads me to believe this is purely boost but that's purely conjecture on my part. I'll try to find out what kind of driver it is.

The MT-G2 can work even at 5.04V and draw 5mA current. The VF at 3A is around 6.3V

Well, on a positive note, if it's not a boost driver then it'll be impossible to overdischarge LiIon cells, as the LED will stop making any light at all before the cells are damaged. :p

Personally I'd rather have a 4S config and proper regulation thru the entire run, don't know why they didn't just do that to start with.

thanks for the review

I am so glad I resisted this one…

Sad to be early out of the gate for a couple weeks and already beaten by more powerful lights with the MT-G2.

I suppose if they get the price down it might be more appealing. $188 MSRP is crazy.

Thanks for the review!

The initial sag is probably the lack of a direct bonded star. My Cutter MT-G2 stars have the same problem. My Noctigon mounted MT-G2 emitters suffer almost no initial sag compared to the standard aluminum star. This light would output 1800+ lumens for quite a while if that simple decision had been made.

Thanks a lot for the review! Frontpage’d and Sticky’d.

How much voltage at two point of led? 6V or 9V?

You do realize how old this thread is? an MT-G2 is ~6V, as noted in posts above. The batteries are configured 2S2P. A new post here caught my eye because I've been looking at my 7G10 to mod up to an XHP70 and FET based driver. it's built like a tank, and a decent reflector size.

MT-G2 has tree type;

6V-3A
9V-2A
36V-0,5A

always 18W
137lm/W

creland is 1860lm,
1860/137=13.57W
13.57W/6V=2.26A

creland’s led driver is almost 6V 2.3A, 13.57W

XHP70 is 150lm/W
13.57x150=2035lm
2035-1860=175lm

it is good result, but big result will be with SMO reflector.

No, for mine, the Crelant driver goes, replaced by a custom FET based driver w/LDO. An SMO will give you the doughnut hole with an XHP70, no difference in lumens, but will get better throw. I'd prefer the OP reflector - it's given good results for others that already did the XHP70 mod.

1860 lumens was spec'd, but not what it really is. I got closer to the results the OP got - mine measured at 1,649 lumens.