Size comparisons:
Trustfire TR-J20, Fandyfire 9XT6, Trustfire X7, Fenix TK70, BTU Shocker
Its worth mentioning that I run 3 x 32650 Trustfire cells in the TK70 and get a sustained 6.22A tail cap reading. While this cell configuration is definitely not recommended for this flashlight, these cells dont even break a sweat in delivering sustained high voltage/high amperage at this level.
Many thanks for the review.
Are you able to put up a beam shot of the TR-J20 against something like an XM-L2 C8? I’ve never seen or used a light like the TR-J20 so don’t really have anything to gauge it against.
With the Amp ratings, you said 3.16A tail. Does this translate to 3.16 x 3 (for 3 cells in series) then divide by 12 (for each emitter) = 0.79a per LED?
Sorry but I dont have any other photo’s for comparisons. There are several threads on BLF that compare beam profiles. Here’s a great place to start.
Someone else might correct me if Im wrong. Since the light is wired 6S2P, I think it would be 3.16/2 = 1.58A minus losses in driver efficiency, etc. If losses were 20% (.316), it would be around 1.26A per emitter.
Sheesh! Im surprised its that bright on that small amount of current. 
That is a chunky monkey. Definitely needs a proper boost in current draw.
I’ve been looking to get one of these for a while just because of it’s sheer size, but something about it just seems off in the comparison shot. I think it’s the giant battery tube.
Chunky’s battery tube is definitely chunkier than the TK70 variety… so its aptly named. Beyond what you get out of the box, it should provide a good platform for many interesting future mods. Im still thrilled with the thick 1 piece floor plate/sink and overall head design. There’s lots of room inside to radically change things around.
FYI
“Pros - tail stands
Cons - does not tail stand ”
What is this fuji white glue stuff you mentioned?
Thanks and edited. It tail stands.
Fujik is a cheap thermal glue used in many Chinese flashlights to secure the emitter star to the light.
http://www.dx.com/p/fujik-silicone-thermal-glue-50ml-grease-like-4579
That thing is huge...and calling my name...must resist...
I'm thinking: boost the stock driver until it burns out in short order (or if I get lucky and it doesn't!), then use it as a contact board, rewire the emitters to 3S4P, throw in an attiny+FET driver, and let 'er rip!
good lord - that makes the BTU look like a v10r LOL
How many amps per emitter would you guess with that setup? …and what are you trying to do? Cook hamburgers on it? If I could find a replacement driver (in case I fried the original), Id like to try bridging the 2 parallel channels and driving 3 MT-G2’s (3S) after the resistor mod.
Edit: Ive also considered tri-boaring it for 9 x 18650’s and a different boost driver to power a 100W 97 CRI Bridgelux RS. Then I could BBQ ribs without a grill! :bigsmile: Id need around 26.7V at 3.75A from 12vin. Yeah, thats not going to happen without more voltage and going buck. All serial for 42.9vin. Hmmm…
Well, in my experience a good 18650 or 26650 will do around 15A into 3 XM-L2s, probably about 18 into 4 XM-L2s due to the voltage sag (32650 will probably be better here, and may see 20A+.) Since it is 3S4P and we have 3 26650s (or 32650s) on the input, I'll bet you see around 4-5A per emitter. Probably best to get some direct thermal path MCPCBs in there! 
Jesus. Potentially the brightest budget modded light on the forum.
I'll bet with some copper MCPCBs and XM-L2s you can hit 15,000 OTF. I don't see any reason why you couldn't. Oh crap, forgot that this is a mechanical clicky. It may need to be converted to an e-switch to handle those kind of amps. That's doable.
On my J18, love hearing the "crack" sound of power when contacting the DMM lead to the battery tube for a tailcap measurement 
. Mine does close to 9,000 lumens, so 15,000 for 12 emitters isn't a stretch.
Yeah, they do that! The boost drivers do it much more though, I think there is a huge momentary draw as the inductor/capacitors get filled initially.
I couldn't resist. Finally ordered one...will be putting an FET driver in there and we'll see how it goes!
It’ll be a beast with a FET driver. I just might need to buy one from you. The best mark I can give this light is in its great heat sinking and sold thick floor plate. Makes a fantastic skull basher too! Please let me know how you like it.
Very nice review Flash. Thank you.
FlashPilot, what is the inner thread diameter of the battery tube? I have no love for Chinese batteries. However triboring for Sanyo 16650 would give a higher quality option with similar capacity. Really looks tight going the 18650 route. This light is really tempting; factory, FET driver or a slight resistor mod.
Great review. Thanks. I have almost bought this light a few times. Still not sure if I’ll pull the trigger or not. But this will help me decide eventually if I want to buy one or not.