[PART 2] Official BLF GT Group Buy thread. Closed, but Public sales open!

I have not asked any one… I am in Virginia usa

I know a lot of USA lights started showing up last week. Yours may still be on the way.

From May 2nd:

Here is his link.

Bedankt Michiel, Jason.
Michiel, do you also know something about tax?

I don’t know anything about the customs fees or tax for the Netherlands. Maybe someone from there who has already received their light can give us more details about whether they had to pay a tax.

Mine came with registered shipping, not DHL, and just slipped through. If they catch it, tax is 21% of the purchase price, plus whatever the shipping company adds as handling costs, in case of DHL in one case that was 18 euro.

i dont know how mine is shipped. hopefully mine also slipps through.

I’m also in the last batch so i’m still waiting.
But all would be send with dhl now so i hope the declared value will be low enough.

GT in action!

In this particular light, if you use high quality protected cells like the 10A ones from IMRbattery, then the only real downside will be cost.

Cheap protected cells can suffer other issues like high resistance but that is the cheap protection circuits.

Are Lost packages reshipping? Is Neal now im LM?

He has not responded to me in a day or 2, that is usually a sign that he is at lumintop or at least away from home. His VPN and thus internet access is seriously limited when it is not at home.

Does this look like a copy to you guys? Or is Astrolux and Lumintop related?

It is 100% a copy.

I know nothing else about it though.

I just happened across it and thought it looked very similar except for the quality :slight_smile:

Ordered may 5th no word yet on delivery or tracking …what do I do next please.

You wait a bit longer, no orders from May have shipped yet to our knowledge. Everything was delayed a bit as they ran out of batteries.

They are 2 seperate companies.

You have not been following its development on BLF these last few months? We talked about it here a long time ago.

It’s not a direct copy. It’s basically a bigger reflector version of the Astrolux MF02 or Mateminco MT35. They started working on it way back when they saw the interest grow during the GT development. It’s running a more basic UI that does 2.5A, but can not do 2A like the GT. So it doesn’t have that longer run time the GT has or the other cool UI stuff you get with NarsilM.

Chinese light makers are always copying and cloning each other. It is what it is.

A driver is what regulates the power between the battery and LED. Electrical current (amperage) is what controls the brightness.

A buck driver is a type of driver that takes a higher voltage and regulates it down to a lower voltage. This is the design in the GT.

Vf stands for Forward Voltage. In this case, we are talking about an led. This one is complicated. I’ll skip it.

GA is the name Panasonic/Sanyo gave to one of their battery models, the NCR18650GA. We tend to say GA for short. Or Panny GA. The Panasonic NCR18650B is called the Panny B for short, etc… The full name is too long to write.

Regulation has to do with the Buck driver design. If you feed it with enough voltage above a certain point, 14.8v in this case, it will maintain a steady output current. 4 fully charged 18650 in series (4.2v each) delivers 16.8 volts. As power is used up from the battery the voltage will also start to drop. Also, as you put a load on the batteries the voltage will sag down a little. Some battery chemistries tend to sag a lot, some a little. The added protection circuitry also tends to add resistance which can cause the voltage to drop more than if it were unprotected. So as long as the driver receives 14.8 volts or above, it can deliver the full 2.5A output to the emitter. This is called regulated output.

Once the driver voltage gets below 14.8v, then the 2.5A starts to drop. So the steady brightness level will start to taper off.

There’s a lot more to it, but that is the basics.

I think you are wrong in lumping together all protected cells. You can’t really do that as the basic cell under the wrapper can have different characteristics. Plus the particular protection circuitry, which is added by a third party, can also very quite a bit.

As you can see here, the added protection circuitry definitely causes an added voltage drop on a 3A load.

The bigger thing to notice is that even without the protection circuitry, the Panny B just seems to have a lot more voltage sag under load compared to the Sanyo GA (and LG MJ1).

In the case of ChibiM, he got a triple whammy. Panny B cells, protection circuitry and only one carrier. The voltage to the driver probably dropped to under 14.8v within seconds of turning on Turbo, hence the reduced output.

When he used both carriers, reducing the load by half, it will take a bit longer before it drops out of regulation. 5 mins? 10 mins? Hard to say.

So I think we all learned something here. If you want to use a protected cell on the GT, you can. Just don’t use the Panny B, use the Sanyo GA or LG MJ1 as they have much less voltage sag. These two will allow the GT to stay in regulation much longer than the Panny B.

If you want the longest run time at the highest levels, then it’s best to use an unprotected cell. (not Panny B, though)

Post 101 here shows how the GT performs with four batteries only. 30Q and KD 3500 protected batteries were used in the comparison.