TrustFire TR-J12 5*CREE XML T6 from DX MF and KD

Safety in RC is a bit different from flashlights. RC you can blow up the bugger with enough smoke as if you lit up a 100 shot fireworks cake and no issue, coz it is outdoors and not in your hand. But a flashlight is often in your hands, plus it is enclosed tightly plus extremely securely (a good tube of 6061-T6 is tougher than you think).

Can you see the blood?

TK Monster explosion :

Nice :) But high current cells usually don't do this without reason, if they do at all. Remember I charge all my batterries at home :) So it is not always outdoors :) My transmitter is lipo powered, I even use liion cells at home to power up home devices. Killed many cells, they always warn you something is wrong.

Yep, for you since you are in RC, you'd have at least the basic skills and equipment to test and monitor. Charging, discharging, testing is a side-line hobby by itself for some of us. Check out old4570/mitro/HKJ's work. But the true is, I think 98% of us here don't even have a basic DMM or lux meter.

But this and good chargers should be something normal. You see what is wrong with cells every charge if you have at least resistance measure and simple thermometer. Past data you can even collect yourself if your charger can't. If you want to say that one light is 5% stronger, it is hard to see with your eyes, you need a meter.

this is why i stopped posting on this website... *drools*

Are you saying my 26650's might explode all of the sudden?

Any of your cells may. But you usually have to hurt them before :) Overcharge, over discharge -too low voltage, over discharge with too high current, physically damage.

Yes but I'm using small magnets on the + pole, because these weren't able to connect in series due to they didn't have the + side further out than the cylindrical body of the body. Any precautions?

I don't like idea of objects which can make a shortcircuit inside flashlight, can;t you weld some material on cell plus to make it higher? Of course many people use magnets and it works, but it is not safiest method in my opinion :)

Here is lux test with 26650s instead of 18650s compared to 2,8A XM-L C8 and 11w 950lumen desk light:

Tail cap readings are with (4,23v) 3x2,1A and with 2cells 3,3A.

Ok, I got my TR-J12 today.

King Kongs do not work in 3x 26650 as-is. These cells have a bit of a recessed positive contact and in order to make a connection between the cells enough force has to be applied to squeeze them together. You can fix this in a number of ways, but AS-IS they don't work. I have not tried 2x26650 yet.

I have some IMR BatterySpace 26650s from a while back and they DO work in 3x26650. these cells have a bit of a raised button on the positive end and it enough to make contact. However, connection can easily be easily interrupted with a slight bump. (The good news is that it takes more than a bump to change modes.)

So unprotected cells will most likely require adjustment to work properly. I'll report back later.

EDIT: The positive contact inside the flashlight is either flush with or recessed in that white collar you can see in the pictures, so no matter how much pressure you put on the cells it's not going to make contact. The head either need a blob of solder, a magnet (at your own risk),or a heavy spring. Even then, with the KK cells you are most likely going to need solder blobs on the positive ends or magnets between the cells. On mine, the force required to make a connection between cells is so great I don't think it could be done reasonably. (Think old D Maglite spring levels of force).


3x26650 IMR- 2.02A

3x26650 A123 (3.2v) cells - 2.4A

Nice! I cant wait for your TK70 comparison ! (hint, hint) haha

ah wait! Its ergotelis who's doing that! oops! :D

Still nothing received from KD though...Ahhh cHristmas times make shipping time quite high....

Im using magnets on my plus side, what risk am I taking buoying doing this?

Just a couple more thoughts/observations:

Nice build quality


One cell operation - it looks like it goes DD (which I think is what we expected) - 4A on a single KK 26650, 1.6A on an A123 (3.2v) cell

Heatsinking seems good, but I haven't REALLY put the screws to it yet.

Could you please test if 2 x 26650 works?

In general? Yes. 2 x King Kongs out of the package? No.

The positive "button" on the KK is the problem. It actually sits lower than the shrinkwrap on the cell.


I just took out the light meter and got 24.9kcd (249 lux measured @ 10m).

(the cells were not fully charged and the light had been on for about 30 sec.)

tip for extending batteries, for those that don't want to solder, and have magnets

wipe anode and magnet w/ acetone or alcohol, put a thin layer of this on anode, then the magnet and let sit overnight (since it isn't exposed to air).

it is basically conductive adhesive but in a much nicer dispenser than a jar. it costs half as much at radioshack and you could do a few hundred batteries. Store it tip down or the tip dries and clogs.