Lumintop GT4

wont 4 sbt90.2 emitters make this a very expensive light vs the xhp70.2 ?’

they should offer both options imo.

Amen brother. :slight_smile:

Is there an official sign-up/interest list?

I’d be up for an XHP70.2 variant myself, but interested in whatever comes out.

Not yet since it has not even been confirmed that they are making it.

Given that the 90.2 takes some 20A plus to really make the difference, how are they going to pump more than 80A through the carriers?

Hey, it’s only 40A per carrier and 10A per 18650. It’s probably the spring loaded button on each carrier end that is the weak link.

If Lumintop is making the mcpcb they could also go 4S. So kinda like the 4S die of the 70.2, but instead of 9A they would need double, so about 18-20A.

It seems a bit extreme.

They would be run in series, so it would only need the 20-30A to power them all at 4S voltages.

I should have bought the damn prototype lol

Crazy, since M4D M4X announced it nearly 11 months ago and said it would be finished after the Chinese New Year. Ah, well, it happens.

bought ? lol isnt thats gonna be sent to vestureofblood ??

Jason, when two carriers are stacked the carrier in contact with the driver has to move the full current load. Even in series there would need to be 20A running through that contact carrier, one spring under the positive plunger with 240 watts flowing through it. I have yet to see a carrier that can handle it. I have seen carriers fry the traces trying. Which is why I asked…

If there is a pack?

2 carriers that each carry 4 18650 cells. The carriers are in parallel while the cells are in series. So technically the second carrier is all about run time.

I have no horse in this race, just trying to help out. IDK if they will even make a 4 x SBT-90.2. Anyway…

I think it was Kawiboy who modded his Lumintop SD75 with a FET driver and 70.2 and drew over 20A @ 6v. It basically uses the same carrier design as seen below.


Pic from Roadlesstraveled

I don’t know if 20A@6v will do the same type of current damage to the carrier as 20A@12v. Maybe? I’m a little fuzzy on this.

I know he had to add bypass wires, or maybe braided copper, to the spring loaded buttons to keep from melting the springs. After that the carrier worked fine.

IF, the carrier damage is the same for both voltages, maybe Lumintop can reinforce the carrier buttons and get good reliability.

Just a thought. This is what prototypes are about, test it, see what needs improvement, etc… :partying_face:

You mean have Lumintop spot weld metal straps to the cells and glue them together in a big heat shrink tube, like an 8 cell battery pack? That would definitely handle the power, but would people want to buy it when they cant choose the cells they want, have to buy replacements from Lumintop and then you have a recharging problem. Would Lumintop need to design a built in charger? That would add even more expense.

Overall, I dont think a battery pack is such a good idea.

Thank you, I wanted to write it similar.

For the GT90, they have already a carrier with 4 batteries in parallel.

GT90

lol, I kinda saw this coming sadly.

I sold the gen 1 prototype since it was no longer truly representative of the final light and I have the 2nd gen prototype sitting here waiting to be sent to VOB once lumintop gives me the go ahead.

The GT90 is using the same basic carrier design (just 1S vs 4S) and it is handling 27A in the prototype according to VOB.

In the GT4 in 4S config the current should be about the same so if it works in the GT90, it should work in this light is my thinking.

Yeah, I pitched the idea 3+ years ago now, it is just not very high on the priority list it seems.