Trustfire TR-3T6 (from Wallbuys) 2000+ lumen mod

Flashlight Modding and DIY Parts
1

Got my light from Wallbuys at their New years sale for 28,11$. Looks nice. I might update with some “exterior” pictures later on, and how this mod will work out.

Modes (measured): 100% 50% 10%, Strobe, SOS

Stock tailcap measurements.
2 batteries: 2,2 amps on high. (2,2x2= 4,4 - 1,47 to each led)
3 batteries: 1,15 amps on high, (1,15x3= 3,45 –1,15 to each led)

Stock, it should be more powerful with two batteries.

Lets see the driver:
Hmm, not the “typical” one.

Better overlook:

My brother who works with small electronics helped me (okay, he did everything).
We/he tried som different stuff had had laying around. He had a powersupply for it, so did several tests with the light in pieces. Different resistors… To make the story short I believe he ended up with one 0,1ohm resistor with long “legs”. This is a temporary mod. Gonna see how it goes over some time.

I have ordered some neutral XM-Ls for this light. (4,18$ each when you buy 3 from fasttech. XM-Ls from this light will find their way into some colored Sipik68s).
I might try to get more juice out of it next time, and also make the mod nicer and safer. Currently, there will be about 1 month until intl-outdoor gets their 9A driver in stock. I would feel better if I knew there was a quality driver soon available if/when this will be modified harder.
I might be very close to the limit though. Same resistor with short legs did not work. Or it may be due to a short, or that it did not work to connect it to the big black thing. Time will tell if my brother experiments more on it the next time I open it up… If it has survived… :laughing:
Current setup:

After mod:
2 batteries: 3,2 amps on high. (3,2x2= 6,4 - 2,13 to each led)
3 batteries: 2,39 amps on high, (2,39x3= 7,17 –2,39 to each led)

Now three batteries should make more light.
Have not tried any high temp/long runtime testing. Ill report back in the future. Especially if it dies. :slight_smile:

For the record. 3 protected NCR 18650B 3400 mAh are a bit long so I will not tighten tailcap 100%. If I should tighten the last 1-1,5 mm I would squeeze the batteries a bit harder than I would like. With two batteries there is no problem. I might modify the light to fix the problem with 3 batteries. But I prefer to use 2, so again, time will tell…

First electronic mod done in one of my lights! :slight_smile:
I would assume around 2200 lumen with three batteries. Not bad for a 28$ light.

2

Thanks for posting! I've got this exact light on the way from Wallbuys too! Might have to give the resistor mod a try. Keep us updated on how it holds up.

-Garry

3

i also have one! i noticed that this one had a sticker on the pill-part, but my DX 3t6 didn’t have that. otherwise they were identical as far as i can see.

might do a mod on my wallbuys 3t6 when i get resistors from fasttech soon.

can it handle the heat? and did you try any tailcap readings with other resistors?

4

Cool, I assumed I was not the only one who jumped on this light on one of the last sales from Wallbuys.

Here is some temperature readings from one guy with quite equal output.

I have still to try out the flashlight for a longer period and higher temps…

Did not do “tailcap readings” with batteries since my brother used some adjustable power supply for it. On that it measured around 3,7A@ 8,1 volt after the mod.
Stock it measured right below 2A@ 8,1 volt, which was lower than my reading with two batteries.
I would have hoped to see around 3,7 Amps with two batteries, but it was lower when the light was put together with batteries. Dont ask me why there were such differences, and why the output was higher with 3 batteries after the mod.

Not sure what values the other resistor combinations gave. But generally he tried a bit lower outputs compared to the one we ended at. We started modding quite late, so time to “experiment” was limited. So far gains are quite nice. About 100% higher output with 3 batteries compared to before modding.

5

I think youre probably going to run into heat sinking issues rather quickly in high mode. Hopefully the driver wont get cooked in the process and medium mode will be bright enough for continuous operation. Good luck and let us know how it survives over the next month of use.

6

Thanks for the info! Just got one of these myself. I also get 2.2a on high with two batteries

7

I cut down the positive spring on the driver. I made it really short. That got me that 1-1,5mm of extra space for batteries. So now I can comfortably fit 3x “protected Panasonic NCR18650B 3400 mAh” batteries.
I could use it without the spring too, but I prefer to have some “cushioning” on both ends.

!!!!!!

This driver can also work as a 3 mode!

—HOW TO GET 3 modes (high-low-Strobe)—
As shown on my picture, connect/bridge the two outer circles that I have drawn RED on with a “green” brige.
Or you can just take off the negative spring and easily re-soldier it to both rings if you place it a bit off center.

Normal. Outer ring only. 5-modes: High- Med- low - Strobe - SOS
Modified: Bridge outer and middle ring. 3-modes: High-Low - Strobe

I also tried to only use the “middle” ring combined with the positve but nothing happened. So I assume this driver can “only” work as 2-mode driver. No complaints on having an extra mode option.
I prefer to have medium mode so I changed back to stock. But some of you might prefer a 3-mode light with strobe. Brightness on high might have been a bit lower, or I have just mixed up the numbers which I did not take a note of. If you prefer the 3-mode setup you should check it out either way, if there was a difference in output numbers it was low.

Oh, and do this on your own risk. It worked on my light, with my type of driver. :slight_smile:

8

nice mod but some mistakes in your calculation. This driver should give you constant current through the LEDs at every voltage…

9

My calculations or my DMM readings? Here are all my tailcap readings before and after on the typical modes.

New panasonic batteries and almost fresh charge. I believe my readings should be quite accurate. MY DMM might be a little off due to loss in wires. My brother measured them, but I cant remember the loss. My DMM and wires generally gave good readings. Eiter way, the before/after difference is done with same DMM, same batteries with basically the same voltage. So they should be comparable.
As you can see on all four measurements (2/3 batteries before/after) they show similar patterns throughout the modes. Those readings have been written down directly into my computer right after taking the measurements.
From the numbers, you can see that the similarities between output difference when using 2 batteries are precisely the same after the mod.
3 batteries pretty much the same after mod too, but with a slight difference in percentage. But still, same pattern as before.
As you can see, 3 batteries gave higher output after mod compared to two batteries. Which was the opposite of before it got modded.
If some of my calculations are wrong, please correct me. :slight_smile:

10

Which value are measured and which are calculated?

You have recognized the paradox with the current by yourself…

Batteries in series have the same current.

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Yes, I noticed that right away. I mentioned it in my first post.
I was very surprised by it! It was the reason why I modified the light to better fit 3 batteries quite fast. I wanted the highest output… :slight_smile:
My readings are the tailcap measurements in the first column. Rest of the numbers are “calculated” based on them.

12

Your calculation is incorrect, I am quite sure with that.
The point is that you can’t calculate like you did, that method should only be a rough approximation.
You get a better approximation if you calculate through the power.
P=U*I
Power=voltage*current

You mentioned a power supply, is it a adjustable experimental power supply?
If yes try this:
Plug your 3t6 on it and try to measure current on some points and multiply the voltage and current to get input power. Do that and you will see that the power is almost the same in every situation.

One often made measuring mistake are to thin wires, these add resistance to the circuit. Because of that the resulting voltage to the driver is lower.
In this case it’s a regulated driver so it will cause to high current results.

That are just my thoughts, I could be wrong too.

13

It IS an approximation, werner. Simple current division, assuming everything is 100% efficient, just to get a rough idea what each led is getting. This method is used for quick calculation.

Though it does seem this driver is not power regulated.

14

Like I said, but it is still false. :bigsmile:
We should not make speculations about the driver without knowing if the values are correct. Best would be if he measures current through the LEDs.

The driver looks for me like a smaller version of the original3t6 one, and this is really well regulated.

I have often seen wrong measurements on this forum, and every time I give a hint of redoing the measurements with thicker wires. You could try this, choose resistance measuring on your dmm and then connect your leads. If it says more than 0.0 you can’t measure current correct on flashlights.
I have done this mistakes in my beginnings, too.

15

+1
As most know, the numbers are just simple estimates based on tailcap current before and after mod. It gives people something to relate to.

My wires are upgraded, and should be ok. Not the typical thin stuff. Out of three sets they are the better ones (thicker, feels better and give higher readings on high current).

yes, that would be the best.

Now…
As for future plans. I have ordered a “battery-box” and a trimpot for easy adjustments when the light is dissembled. Parts are on the way… Or, they will be when they are shipped… :stuck_out_tongue: Hopefully they will be out of HK before their holiday.
Might take several measurements in the future to get a better picture of the performance with 2 or 3 batteries… Ill report back…

Still have heat tests to do with current setup… :slight_smile:

16

Nice!
Are your measurements with 3 batteries almost the same as mine too?

17

Thought Id do an unofficial light test with my phone (galaxy SII) and an app called light meter.

Same results with 2 or 3 batteries. I tried back and forth several times. So maybe the output is regulated after all…
Ill defiantly do some output measurements with a DMM in the future. :slight_smile:

18

Well, 1. phone sensor may not be the most accurate and 2. there isn’t much difference anyway since it’s 2.2A vs 2.4A .

I’m waiting for mine as well, $24 on WB third sale. I didn’t even plan to buy it, it just happened :stuck_out_tongue: Will do comparative measurement against yours when it arrives.

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These are my “private” notes, so hope they should be easy to understand. Orange column are temperature readings (Celcius) and some voltage readings… All readings done on high. IR meter was used. Light was tailstanding on my floor. This is the modified driver with higher output.

Conclusion after testing:
-That is one tough light in my opinion! I made it shutoff three times! Usually with small breaks before it was back on.
-For me (im used to P60 light driven at 2,8-3,7amps). I would consider the heatsinking to be sufficient for high output. Almost twenty minutes on high before it reached 60C. And with a bit cooldown, the light was still warm throughout the whole body it almost did another 20 min on high.
-It has some sort of built in overheat protection that works between 60-70C. Either complete shutdown, or it steps down into medium mode and locks all modes. (Im pretty sure it was on high after changing batteries. I am aware that it is easy to change modes when the light is tail standing. )
-By looking at tailcap readings when batteries are 3,9V and 3,6V. I would say this light is regulated! :slight_smile:

This seems to be a good driver. It has some nice features and seems to be well regulated. (Looks like Werner was right about the regulation. My phone measurements was probably not that bad either.)
I plan to do simple overheating test with 3 batteries within 48hours… Might give a small report on how it goes…

20

This is a really nice light and for under 30$ everyone should have at least one.
The pills are quite different depending on which manufacturer you get.
Mine was quite long but didn’t touched the body so good so I added a bunch of this white rubber like thermal glue before screwing it together. Seems to me that after that the light gets faster hot on outside of the case.

Was it really a thermal shutdown or ran the battery in the protection?
You have to think of that this beast now pulls 3A and up, the lower the battery voltage the higher the current so it gets empty faster and faster…