BLF GT official support thread [FAQ updated 11 Jan 2018]

The GT was tested with 30Q and Panasonic 3500mah cells (2A at the emitter). Which should be pretty close to the 35E cells.

You’ll note that with the 30Q it stays in regulation a bit longer due to less voltage sag, but the 3500 cell has longer run time. So it’s a bit of a tradeoff.

Anyone else found the 30Q batteries to be a bit too loose in the carriers?

I assume you mean the springs are not compressed enough to keep the battery from wiggling side to side?

This is normal. The carriers are designed for both short and long “protected” cells. So that is about 65mm to 71mm. With a short cell the spring is only partially compressed.

What about the swap of the original led to the CFT-90 one?
I wait until some other guy tries this,so as to see if it is sensible to raise the high cost of the procession.

Vinh over at Skylumen is doing this swap. It has nothing to do with Lumintop or BLF.

Indeed it is a nice mod but not practical for production. So it will be left to modders to do it.

Besides there needs to be SOMETHING to mod or it would not be a BLF light lol.

If you can check my understanding, I would really appreciate it. I do not understand this stuff too well. Looking at this chart, I get the impression the BLFGT does not have to step down to avoid overheating. It looks like it can run at max output as long as the batteries can run. Is this partly correct?

It does not overheat. It will step down if you add heat to it like with a blow torch, but with just the emitter, it should not get hot enough to step down.

At 2.5A, the xhp35 only puts out about 36 watts and the flashlight body is massive with lots of surface area.

The general rule of thumb with really big lights like this is that they can usually sustain about 4k to 5k lumen continously. Some can do 6k and I think the best is the Imalent DX80 at about 7k lumen continously. Any higher than that you’ll need to either step down the power or add active cooling.

Correct, even under extended loads it only gets up to around ~55-60c IIRC, which is still considered “safe”.

The thermal protection is set from the factory at around 65-70c I think.

Now an XHP70.2 is another story, that will need a thermal stepdown but it still lasts a long time before overheating.

Thank you for the information, much appreciated.

I am sorry if I should have seen this elsewhere, but has an an XHP70.2 been run in a GT host yet? I am curious about the candella/throw figures.

Also, am I correct in understand the gt with the XHP35 is the strongest thrower in a hand-held light? Hummm, I guess Vinh can put a new type of LED in that has a smaller diameter making the whole throw process more efficient.

I am picturing Earth with 850 BLF GTs, imagining that apart from maybe a few dozen custom built exceptions, those 850, soon to be 1500, BLFGT lights are the most powerful hand-held throwers ever built. To me, that is so awesome, with a small caveat. The caveat is: it is awesome if true!

Is it true?

Yes, I have 2 xhp70.2 GT’s now. The first one I built with a modded stock driver a few months ago. I tested it at over 1300m of throw with the dome on and ~1600m of throw with the dome sliced off.

Lumens were around ~7000-7500.

The GT is the furthest throwing production LED reflector light in the world right now. With another LED it can throw further but at the cost of something else, either lumens and spot size or cash.

I just got my BLF GT in today and it’s now dark.

I just realized that the battery carriers are protected against flat top cells, and even my solder-blob-top cells don’t reach far enough to make contact. :person_facepalming:
It’s 2 AM and I’m far too tired to solder the carriers or more cells. :cry:

I will say the BLF GT is short compared to the TRJ-19 and TRJ-20, but the head is HUGE.
I need a handle for this thing, I was starting to get a cramped hand holding for a short bit. That said, I wish I could get an extended tube and use 3x battery carriers! :smiling_imp:

My GT arrived today. I am making a video of it performance on urban targets, such as the major league baseball stadium a few blocks from where I live.

Everything about my light is perfect. I read something a few months ago about the clicking sound in the glass from thermal expansion and contraction. I don’t remember if that is a potential problem, such as cracking the lens.

This light makes everyone in my house giggle.

OT: Out of curiosity, what can we expect from future LEDs? What could be the throw and lumen output of a BLF GT in 5 years?

I am sure things will continue to march forward, although it seems most development is towards larger high output LED’s and not so much thrower LED’s.

Just got my BLF-GT!!!
So excited… except for one thing: I only received 7 batteries!

Not sure who to talk to about this. The whole point was to get 8 matching batteries to use for this badboy!

Help?

Send Neal a PM about this.

Got my BLF-GT a few days ago. As we pretty much have have daylight all the time now in Sweden, i have not been able to test it outside yet. But I’ve tested it indoors and it worked great. A couple of times. Now not so much. I get as much light out of it as a key chain led light. I have tried the factory reset, and I can see that it ramps up from very low to only low in just about 1 second. All batteries are brand new and fully loaded. When i connect the batteries the GT flashes 2 times. What could be wrong?

This is really odd, I’ve never heard of this before.

What happens when you double click to turbo?

What battery voltage does it blink out on a triple click?

Double click gives the same as ramping up to max. Almost no light.
Triple click shows 4,3V.

Here is a smal video clip: Dropbox - IMG_2207.TRIM.MOV - Simplify your life (disregard from the cat noise :slight_smile: )