ZY-T08 Mod - picture heavy with beamshots

That was your FIRST mod ???!!!
Amazed.

I can already tell you that the emitter has a high vF. All of the new XM-L2s I've tested have a high vF, and since it is a U3 it is a newer XM-L2.

Thanks again to all of You guys and for Your answers and comments :beer: . Good feedback is a real boost.

Made some measurements and these are the results:

DMM wires (12 AWG) 0.1 Ohm
From tail cap to pill 0.2 Ohms
From contact plate (battery side) to led+ 0.2 Ohms

Freshly charged ultrafires, both 4.18V
Hi 3.79V at led + & -
Med 3.02V
Low 2.69V
Moon 2.58V

Does these numbers confirm high Vf?

Yeah, that is pretty high. If you look at djozz's chart above, his older XM-L2 had a Vf of about 4.65 3.65 at 4.4amps. Decent cells will sag to 3.9 volts under even at just a 1 amp load. Sounds like you identified your issue. High emitter Vf and cell voltage sag.

Bet you're even happier to have some 25R's on the way now. Please report what they do tail current wise. I'm curious.

Great mod!

I got one that had horrible corrosion in the switch and I wasn’t sure what to do. Your plate on the tail is perfect. Thanks for sharing.

Nothing else to say except, Awesome mod!

Nicely done and very creative! Keep up the great work!

That’s a nice mod :beer:

Lot of work there. It might be the angle of the picture, but in #31, the +LED wire looks awfully close to ground?

Yes, it looks that way. Take a look at the picture 28. The pill is around 2mm below the wire. I had to move those wires as far as I could to get clerance from reflector bottom since it is sitting on the MCPCB. That’s why I sanded the edge of the pill down.

Ahh - I see :nerd_face:

:beer:

That explains everything, thanks.
Don’t get me wrong, I couldn’t tell the difference in amount of light emitted between 4.5A and 3.8A. Maybe that’s only my inexperience . This thing throws like crazy even at lower currents. Although it would be nice if numbers were like they supposed to be. Hope that 25R’s will help. Can’t wait :slight_smile: .

Cula wrote:

. . . I couldn’t tell the difference in amount of light emitted between 4.5A and 3.8A. . . .

I think that is normal due to our perception of light and our ability to adjust to different levels of light. Where I have noticed a difference the most is in throwy beams. I have some lights that have some obnoxiously close modes. The extra current makes a difference when I'm trying to see on object far out towards the edge of the usable beam. I need, however, to switch between modes to see the difference. Well, I can also see the difference close up in the intensity of the hot spot when switching between high-level closely spaced modes, but I don't like doing that.

you have done a great job!

thumbsup

Some of what you did is time consuming pain-staking work, you made it LOOK easy! Nice job!

The new high Vf makes it more difficult to pull high current, BUT they make more using less.

To my findings they’ll typically do about 2A less at the limits, but only lose about 200 lumens. Very similar output, much less current draw. Efficiency working hard to give you longer run times. :slight_smile:

You should see more from the 25R’s but don’t expect a lot more, what you’ll see though is a little more and it lasting longer as the higher quality cell maintains during the current draw.

Enjoy that light!

Fantastic job! But hardly just for newcomers, you re-manufactured a couple of sub-systems there. Maybe try a couple of 4.35V cells.

If you get 4.35v cells, get the LG D1s, not the E1s. The D1s pull more amps. A freshly charged set of 25Rs will still pull slightly more amps than the 4.35v D1s on the newer emitters, but after a few minutes the D1s pull ahead.

These LGD1’s look very nice. I was thinking of buying them few weeks ago but that meant I’d have to buy new a charger so I gave up on that deal. We’ll have to wait till 25R’s arrive and see what happens. If freshly charged ultrafires gave 4.4-4.5A it could only be better with samsung’s. But frankly, I don’t give a damn. Even if it stays at 4.5A it throws farther then I need.

Just for the sake of my mind, is there a way to push these new XM-L2’s beyond 5A without using a buck driver and 2s cells?

They fry quicker than the old ones.

Sir, if this is what you accomplish with your first attempt at modifying flashlights than the old hands here will soon be learning some things from you. Very well done.

I owed this information when 25R’s arrive so here it is.
Max tail current measured (1s2p) is 4.55 Amps when freshly charged to 4.20V but Samsung’s hold voltage very well under load, much better then ultrafires. I suppose that with two parallel 18650’s this is as good as it gets with newer XML-2 emitters :beer:.
Just wondering would FET driver push this emitter higher than this.