Hi, this is my first post here so please feel free to point me in the right direction if I say anything wrong.
I have been using 18650 flashlights for a little while now. I mostly just use these for walking around the park at night, or working on the car. Anyhow, the other day I decided to pickup a “bigger” TR-J18
I got the flash light along with a full set of new trust fire flames. They do seem to be original as they have the hologram on it…. The problem is that for some reason the light does not seem to want to turn on.
Let me clarify.
With 3 cells in the flashlight. I am getting medium and low modes. High, sos and strobe results in a quick flash followed by “nothing”.
Now the funny part is that with only two cells in the flashlight, (the same two cells I might add) it works fine. I have always through that running more cells = easier on the batteries = have less trouble… But if 2 cells works, why would it not work with 3?
One more thing to add is that running 3 cells, in medium mode (or what I think is medium) the flashlight looks to be as bright as it is on high with only 2 cells in it… which leads me to think that that there is more output to be had in this light.
Anyhow, if anybody could give me an idea what could be wrong… do you think it’s the driver unable to handle the voltage? or the batteries protection circut shutting down?
You've confirmed that all three cells are at full voltage? And does the same issue occur regardless of which of the three cells is removed from the light (so the issue can't be traced to a defective cell)?
Yes the cells are at full voltage. All cells are new and on my old (and not super accurate analogue) meter are showing about 4v at full charge. All the batteries are reading the same.
The cells are 18650 trust fire flames, 3000mAh. I bought 4 of them so I do have a spair to “swap out” as needed.
The light will work perfectly with 2 cells.
With 3 cells, I have the quick flash then “nothing” problem when the light starts up on high… BUT…. if I switch modes down to a medium, let the light run for 10 seconds or so the… all the modes will work again.
If the light is still warm… all the modes works fine.
I have a hunch it’s something to do with the cells… maybe I’m tripping the protection circuit on one of the cells for some reason… not sure why.
I’m going to spend a bit more time swapping out one cell at a time… maybe one of the cells is marginal.
That’s what I was thinking, maybe one of the cells is bad or just not functioning well. The J18 uses a lot of current, almost 9A in total. You should get some 26650 Trustfire batteries, they have a much better capacity and will handle the high current better than the trustfire 18650 flames.
Yes it is one of the cells. After a process of elimination, there is one cell that will cause the flashlight to just “flash” and not turn on. For some reason the cell will work fine in my other lights and will even work when “warm”.
Thanks everybody for the help……. now for a slightly different question.
Is it necessary to mod this flashlight to make it more reliable? I remember reading on here that the tail cap spring will melt running 2 cells…… but looking at the tailcap I see a “plunger” style end… not a spring like they show in the post. Is the spring “inside” the cap?
I've been seeing some newer TF 3000 flames not working in direct drive lights (high amps), while older ones work fine. So, there's something that changed or "bad batch" situation, I'm not sure. I've seen it on 2 newer TF 3000 flames bought together - these were bought from LightMalls.
Update: Got a J18 on order from FastTech, but ordered the TF 26650's for it - best when run on 3 26650's from what has been said here on BLF.
I think you need to unscrew the plunger to get to the spring if I’m right in what you’re describing. Yes, I would add some copper braid so it can handle higher currents, especially if you’re using it with 2 cells.
The light works in all modes and with 2 or 3 batteries. I took the light apart and did manage to add the copper braid to both springs on either end. The problem. Hi mode is the same brightness as the medium… and low looks pathetic.
The worst part, the high mode is dimmer than my ultrafire kf-t60 (or my small sun zy-t13).
swapping batteries around for a night, and trying the “paper clip” trick on the tail cap has not helped
So… does anybody have any suggestions on what could be wrong (again?)…. OR… does this sound like a good time to upgrade the driver?
I really only use this light to light up my backyard from the house… and for the “ooo wow” factor. I want LOTS of output for the oo, wow factor and a low mode for normal use of approx 1000-2000 otf lumens.
