As is from the factory I get on three fully charged Keeppower 26650’s 5200 mah. It drew 3.04 amps off of full batteries and climbed to 4.54 amps when it shut down at 9.6 volts. With a 1 ohm 1/4 watt resistor I got the following chart. All voltage checks were done without load.
at 10.15 volts the fun starts in about one minutes running time the amps runs from 6 to 8.9 at that point the voltage sag hits about 9.5 volts est. and the low voltage safety kicks in.
A 1.8 ohm 1/4 watt SMD in addition to the already added 1 ohm 1/2 watt resistor. Light was cooled between each measurement for the readings.
These two resistors added gave me a quick and easy mod. Further added resistor got the MOSFETs roasting hot. So the light currently stands at this level, bright with some run time. No component failure yet.
As a disclaimer these reading were done with a cheap meter when I run two of the same meters parallel with a single set of heavy probes wired to both I usually get a reading about 10% higher.
How can we know if this is a real tr-j20 or a clone? Texas Shooter is your light from gearbest and did you purchase it recently? I received some fake convoy s2+ lights from gearbest so I'm a bit leary of them at the moment. I will add that they did send me a couple of real s2+ lights to replace the fakes so that part was good.
Well I don’t know yet. I ordered a few days after posting and it’s some where in Tennessee right now. I’ve never heard of a tr-j20 clone, it’s a pretty big light too begin with. I did get one from Fasttech when they 1st came out and was happy with it. None its parts look like any others so cloning should not be an issue. As far as the LED’s I’ll post if they are Cree or Chinese knock offs.
That is a great deal... Though the last lights (two Y3's) I got from GearBest were all banged up, but Karen helped got me 60% back on them, while GB cust service offered 10%.
As long as the TR-J20 comes to them in a good box ready for shipping, pretty sure the packing should be fine. Karen is saying they are gonna improve but we'll see. The GB busted bubble wrap can't compare to BG's foam wrappings. This light is big and heavy, so packing is vital.
That’s an interesting point Tom E. My J20 came in a heavy cardboard Trustfire box, with form fitting styrofoam holding everything in place, so it was virtually bombproof for shipping. Not sure if all J20’s come that way or not.
I think someone mentioned that they received a J20 recently that came with XM-L2’s, but I cant find the post/correspondence now. I’ll keep looking.
Mine also came in a heavy cardboard box, with Styrofoam and the wrapped in plastic, with brown paper covering the light. Would like XM-L2’s but if not it’s getting XL-P V6’s. Then the usually current bump. This one does scream XHP-35’s in parallel, so maybe that.
It finally made it here a couple of days ago. Quality control card indicates it was inspected on 10-22-2014. Very much has genuine XM-L probable T6’s, XP-L V6’s are going in soon. Just the LED change should add about 33% to overall brightness. Tail reading with the same three fully charged Keeppower 26650’s 5200 mah as used in the first one reads 3.35 amps, 10% higher than the first. Only other difference noted is this one has a serial number on the bottom fins edge. Same weight, same skull crushing strength with a thick body tube. This time the light was only wrapped in two layers of bubble wrap with no Styrofoam. No damage or scratches noted.
Glad to hear it arrived in good condition. Mine shipped yesterday, now I just have to wait for it to arrive. I've never had an expedited package from China ... I'm used to the standard 6+ weeks to western Canada. Speaking of which the 32650 batteries from fasttech are going to take a looooong time to get here.
Do you have a light sphere or any way of testing the resistor / lumen ratio? I'm curious to find out if after a certain point all you are doing is tossing a large chunk of the extra power into heat. I'll search the forum some more and see what i can dig up on it in regards to the resistor mod.
I don’t know. It seem as bright from start to end of the battery test but without a ceiling bounce or a light sphere it’s all guessing. One note on the amp run away towards the end where voltage sag takes over and turns off the light current shoots up wattage shoots up, light stays the same. And that happens in about 60-90 seconds. So my guess is the sweet spot is on fully charged batteries and everything else is lost efficiency. But hey it’s all fun to experiment with. This light is as tough as they get with great heat sinking. This is the experimenters dream. It does need an after market 3x3 18650 replacement tube. New threads will have to be cut.
I guess I'll start without any mods and see how bright it is. Then I'll toss in around 1/2 ohm and see how hot the components get. If the driver blows up I'm not overly concerned as it gives an excellent excuse for a new/better driver! I really would love to have DD output that was temperature controlled. Don't get me started on the stock UI on these lights ...
Do you know if the stock driver has low voltage shutdown/warning?
Great news about the low voltage cutoff, thanks. Once the current gets past 6ish amps the protection circuits on the Trustfire 32650 cells will need to get removed. I'm glad there is still some protection for the cells in case I have a brain fart. Let's go play with a 3s potential pipe bomb ... whee.
I had RMM build a FET driver for mine, but never installed it to avoid the potential mega pipe bomb scenario. That, and having to rewire all the emitters. I purchased my cells as unprotected, but those dont seem to be available any more unless we purchase through Trustfire direct. Removing the PC from protected cells looks simple enough.
i dunno why… but i keep imagining that TrustFire TR-J20 modded with 12, MT-G2 emitters because of its massive heat fins, and a custom remote 50-amp shoulder-strap carried battery pack.
Why stop there when we now have XHP-35,50 and 70. XHP-35 being close in size to the XM-L, with an extended 4 cell tube they could all be wired in parallel. That would almost be practical, and a new throw/flood master at what 1500 lumens by 12 LED’s 18,000 real lumens or 1,000,000 Chinese lumens.
Anyone think we can get Dale, Old Lumens and a few others to mod this one through the roof. Say cut a new tube for 3x4 18650’s and use 12 XHP-35’s. And all this on a super Mountain Electronics custom driver.
TS,
How hot does this thing during the 15 - 20 minutes of run before it starts sucking the batteries down? It looks interesting for checking out what the dogs are barking at…
I did remove the protection circuit from a TF32650 a few weeks back, very easy. A buddies pack of batteries arrived totally soaked with ?water? or something. The TF32650 was the only battery that had low voltage when we checked them. I tried using my Imax B6 to charge it (in a well ventilated area). The battery acted screwy so I removed the outer wrap and the PC almost fell off. It looked to me like the PC connections to the battery had corroded and were only making contact due to the pressure of the outer wrapper. Even if the connection had not been corroded removing the PC should not pose any real problems so long as you respect the cell. Once the wrapper is off the top of the cell has + and - in close proximity. Insulating the top it with kapton tape let me breath easier. In the end the battery still has good capacity and he is getting another one shipped out to replace the original. I'd call that a win.
With the exception of the Olight X6 Marauder, the J20 is the only other stock “high powered mega flood” LED light (that I am aware of) that can sustain continuous max mode for as long as the cells can provide it. I own both. :bigsmile: Pushing the power levels any further on either light will overheat the head. For a modified J20, that’s why we have lower modes to drop back and thermally regulated drivers.
