Yep, I checked and the coupon code stills works.
I’ve been trying to figure why there isn’t more hysteria about this light at this price. Great light at a great price with a proven vendor. I guess people prefer the form factor of the King better…
After seeing the issue Kramer had with his tail-spring, I decided to modify mine before a problem came up with it. I noticed the switch was the same on my Skyray 856 except the 856 uses a stronger gold plated spring soldered to the switch rather than a thinner chrome plated version as on this J12. Since my 856 has a bad driver, I figured I’d just switch them out. Works great and I doubt this heavier duty spring will suffer from any heat issues.
It’s down to $53.80 at DX now too.
I can think of 2 main reasons. Size factor first and foremost. Its just a pain to pack a 2-3, 26650 light, IMHO. I think the bigger difference though is how each design makes use of power. The J12 needs 3.6 - 7A from each of its cells in its smallest configuration. This IMHO pretty much rules out 18650 cells as a safe alternative. This is a very difficult load for even the best 18650 cells. Even 26650 cells, if continually deep cycled with this extreme of an application will start to feel the effects. Exactly how (and when) remains to be seen… increased internal resistance, diminished self discharge performance, decreased capacity.
Because of its power extremes I don’t think the J12 is a light suited for a battery novice. I don’t think its the kind of light like a 4D maglite where you can just load it up and run it till’ it dims, at least not repeatedly without unfolding some element of risk. I for one also don’t think its a safe practice deep-discharging protected cells and tripping their circuits. So I think the J12 is the kind of light that requires some disciplined use… But thats just IMHO.
Looks like the J12 has been reduced in price since I purchased mine from them for just over $53.00 recently. Now $50.39 delivered.
I have one of these on order from the same supplier - so far 13 days and counting for delivery. The tracking number they supplied me does not work though…
You can buy it with Paypay from http://www.beltal.com/dhgexpress?uri=/store/product/1PC-Trustfire-TR-J12-Flashlight-5-Mode-4500-Lumens-5-X-CREE-XM-L-T6-LED/604837_548149376.html
Mine arrived today.
I’m getting 4A at the tailcap from 2 trustfire cells at 4.02v each.
I’m getting 5A at the tailcap from 2 MNKE IMR 26650’s at 3.99v each.
Aaand the +be spring just melted after 3 mins in the MNKE’s
Yay.
How much current is the DRY NW drawing at the tail? Is it the older T5 4B NW tint offered first or the newer T6 3C NW?
I have forgottent how much my T5 4B is doing, if i remember correctly it probably is just 2100-2200 lumens or so.
I’ve replaced the spring with a much heavier one, and now I read 5.5A on the MNKE’s 
And that’s with thin leads on a multimeter. I suspect the amps through the switch are somewhat higher.
I wish I had a lightmeter to compare with my other lights.
I have the tr-j18 i would buy the the j12 if they didn’t lose 10-15% output power witihin 10-15 min do to heat.
Ok, I’ve used a lux meter app on my iPhone to get these results.
They’re relative, at least 
J12 on IMR : 735lux
J12 on Ultrafire: 705lux
Mac’s Customs 3300l (High CRI, warm tint): 600lux
Multiple readings were taken and averaged over a few minutes.
The 3300L costs literally 10x as much as the J12, has 9 XP-G’s at 1550mA each.
The current hotshot is the Trustfire X100. Unfortunately the J12 tube does not fit. In 2S application, it is close to 4000 lumens OTF.
I’ve got the KD driver on order to upgrade this to its full potential.
I’ve been running a full-burn stress test over the last hour or so. The batteries were charged to 4.20V and the light is tailstanding on a table in the corner of a room with no air movement. The iPhone is laying on the table next to the light, measuring the ceiling bounce lux. The results will mean little compared to someone elses results, but will give a good indication of output loss during the burn.
The results so far:
0:00 - 735 Lux
5:00 - 705 Lux
10:00 - 690 Lux
20:00 - 675 Lux
30:00 - 665 Lux - now too hot to hold
40:00 - 655 Lux - tube now uncomfortably hot.
50:00 - 645 Lux
60:00 - 640 Lux
I’ve no idea how long it will continue to run - I bet not long 
It’s lost 15% of its output from cold to being too hot to hold on to. Not bad for my book.
EDIT: 70:00 battery PCB cutoff
Ok, that’s good. From now on it’s not recommended to gun it like that. Try to keep it within 20 mins will ya (that’s a long time actually). Best is not to go over 15 mins. These are budget lights, not CPF style stuff. As you can see, under 10 mins there is not much heat sag at just 6% which is absolutely invisible to the eyes, that’s very good in my book for a > 2000L OTF. Its a apples - orange comparison, but try this with a SR90.
If you need more output or approx the same 1600L output for 1hr runs, get the X100.
The good news is that while the light was cooking, the batteries stayed at a safe temp. No risk of Darwinism, just a dead light
Also, the batteries came out at 3.05 and 3.00 volts. Remarkably well balanced for trustfire cells. I’m pretty happy all up.
I like to give things a hard workout out of the box so I know their limits. I’ve been around long enough not to hurt myself, but sometimes I do hurt the equipment
Hi 2100, My DRY is the later version with the T6 3C NW with the auto-stepdown feature. With Redilast 3100’s, it would start as 3.65a and slowly climb from there.
There were reports of dead drivers on DX and/or MF. Coz these drivers do regulate and boost up the current if you are on 2S, which can get pretty high. Do it often enough, and with heat, it can go.
For the DRY triple XM-L there is no issue, coz the drivers are only 5 bucks each. The KD “replacement” for this is 20 bucks, but you do get 4000L OTF!
It’s actually the same as say the SR3800. I have gunned this first triple XM-L light for over 20 times from start to finish to time the runtimes of all my cells, but cooled with water (head portion). Luckily i had XTAR 2600s in it failed (no light) and it presented a dead short. If it was some unprotected cells, my whole toilet would be finished. (maybe only the Panasonics NCRs would withstand a dead short). And this is not only the sole failure, there were quite a few more reported here.