Lumintop BLF GT94 ( 4 x SBT90.2, 1.65mcd ) NOW AVAILABLE @ Neals: code NDGT94 gives $ 150 off

What changes need to be made to the GT70 driver to up the current for 4 SBT.90s in series?

Technically the GT70 driver would work as is but swapping the FET would be a good idea.

There are some other PCB changes to the GT4/GT94 drivers to beef them up and reduce voltage spikes and improve longevity but they are not possible to implement on the GT70 driver. The GT4 driver also has the programming key to make re-flashing easier.

Today, on the German forum, HARDUS posted GT4 and GT94 comparison beamshot video: https://www.taschenlampen-forum.de/threads/lumintop-gt4-incoming.68291/page-2#post-1088768

Thank you, HARDUS!

Just thought this thread might be interesting for some of y’all.https://www.candlepowerforums.com/vb/showthread.php?471366-BLF-GT94-vs-HID-LED-has-surpassed-HID-in-my-opinion&p=5423310#post5423310

Just skimmed the first page, Good results in the OP and nice beam shots.

Many misconceptions and wrong assumptions further down.

Example, the temps, 100C is perfectly fine to run 24/7 for the internals of the light and would actually be considered fairly mild to most of the components. The rated temps of the components are what they are rated to run at 24/7 for the rated lifespan.

The cells on the other hand are the weak link with a max rated temp around 80c.

Now 100c is NOT something you would want to touch bare handed, that is for sure!

What do you mean with programming key to make re-flashing easier?
Is there newer UI planned or switching to Anduril UI?
Narsil M V1.3 is great for me. But in Some lights, which I own, Anduril is great, too.

Thanks.

It is a series of exposed pads on the bottom of the driver that allows you to reflash the driver without removing it. It uses the lexel programming key.

It is only for modders, there is no official support for that feature but I added it for those that wanted to use it.

Thanks.

So it´s like contact pads an noctigon drivers which I have in Emisar Flashlights for example.

Is this the programming key:

Thanks.

One more Question. In Video from Matt I saw the batterycarrier with screwing.
Is this a 4S2P carrier? Why this screwing? 8 cell carrier for unprotected cells with full compressed or bypassed springs would work two? Or is contact resistance to high?

Has someone still got his GT94 and can show some pictures of battery carrier?

Maybe I would like to use LiPo Airsoft batteries, if I will find some, fit in the batterytube.

Correct and yes, that is the programming key.

The screwing down of the carrier was the best solution we could figure out to both keep resistance low enough to carry 30A+ and fit a variety of cells.

We tried normal springs but had issues with them collapsing due to the current. I tried to get them to use some super beefy double springs but they chose to go this path instead.

The screwing actually works fine, the issues people have seem to stem from the narrower spacing on the rods then in the prototype, combined with the plastic sleeves this causes binding on the cells and makes it much harder to get everything lined up.

If you remove the sleeves it is much easier to tighten but harder to get everything lined up.

It is possible you could replace the sleeves with shrink wrap that would not bind as much.

Finally got my SMO reflector from Neal. Replaced the OP and measurements were as followed.
OP 1.4Mcd

SMO 1.583Mcd

Measurements done at 2 seconds from switch on.

OP

SMO

Not bad, about 13, pretty close to the 10 I have seen on average in the past.

Nice! We’re there any unwanted artifacts in the beam or noticeable donut holes that you couldn’t see with OP reflector?

yeah not bad. Must say I’m impressed with the SMO reflector.

You guys are :sunglasses: !

:+1:
:beer:

Thanks man.

Hey all not sure if this is the right place to post. I recently bought the GT94 and have an issue with the battery drainage.

I’ve used it a couple of times already, and every time it only drains some of the batteries while leaving the others completely untouched. Sometimes it drains the pairs in series, sometimes the ones in parallel, but I’ve never managed to get it to drain all 8 at once.

I’ve seen Matt’s vid, and made sure the batteries were completely tight in the carrier, and all the buttons were inside the rim where it’s supposed to go. Is there something I’m missing?

First check the carrier and batteries over to make sure that all the button tops are the same and in place and that the carrier protection pcb’s are correct. Someone reported that one of the buttons came off the carrier that preventing it from making contact.

After that, make the bays that are working with tape or something and see if the bays that drain the cells are always the same.

FYI, it will always drain at least 4 cells, the carrier is setup in a 4s2p config so at least 2 sets of 2 cells will be drained or the light will not work. Now which bays drain can change, that is what you want to narrow down, does the bay that drains follow the cells or the carrier.

More then likely the cells you are using are borderline for contacting the protection buttons and that is why they are not reliably making a connection. A small solder blob on the top of the cell should fix it in that case.

Thanks. I’m using the Sony vtc6 button tops which is what most people seem to be using. The battery carrier seems to be a really tight fit so I’m trying to remove the rubber sleeves to see the batteries will fit better. However a few of the torx screws on the carrier are stripped so I have no way of taking the sleeves out unless I cut them open. Wondering if that’s worth a shot.

I think the screws are hex head, not torx, might help?

You could cut them off, it will make it a bit harder to line things up but easier once they are lined up.

All the buttons are in place on the middle PCB’s? if evreything checks out on the carrier itself, then must just be a variance in the cells, one of the button tops might just be a little different then the rest and doesn’t seat properly.

Do you have another set of cells you can try just to see if you can get all 8 to connect?

You’re right, they’re hex not torx.

After a bit of trial and error I finally managed to get all 8 to discharge. Turned out I really had to massage each battery in place, screw in the tailcap, massage then screw in again and rinse and repeat till I absolutely can’t screw it in more. All the buttons are in place and all 8 batteries work.

Still I’m considering taking out the sleeves. Holding the batteries in place is the easy bit, lining them up properly takes a bit of effort and there’s no indication whether or not they’re all seated properly. Thanks again!