Lumintop GT4

will the GT4 beat the new R90TS? someone measured it at 30,780lm/1796m throw

Beat? Sheer lumens no, certainly not. Duration of maintaining a high lumen output, most likely. Remains to be seen though as the GT4 isn’t out…

Any updates?

Wondering also!

I wish I had something to tell you, they have not given me any updates since the last I posted here for some reason.

Hey all, given HKJ’s review of the Vapcell INR21700 4200mAh (Test/review of Vapcell INR21700 4200mAh (Green) 2019) and how much better it is than the Samsung INR18650-30Q 3000mah and Sanyo NCR18650GA 3500mah on with high currents and runtimes, I really think this light should be designed to fit them.

It's been discussed a couple times in this thread already, probably too late at this time. With the 30T and 40T out and available for months now, I don't see how the Vapcell 4200 changes much of anything. Compared to the 40T on HKJ's comparator, not much difference.

Ah, I must have missed that, and didn’t even know about the 30T and 40T. Been so busy at work, don’t get all the time to read forums as I would have wanted. Thank you for the answer

Yeah, 21700 has been suggested but lumintop feels it would just make the light too heavy and I can’t say I disagree. It would add over a pound to the weight based on their calculations and this light is already tiring to hold.

Personally I am split 50/50 on it, I can see both sides.

Me too. But then again, we won’t be free holding it for the most part. It’ll be on the shoulder strap. I wouldn’t mind either way

hm a light this size u arent really meant to holding in your hands a longer time, using a neck strap should be the way to go, then another pound or not wouldnt matter.

how much does the gt4 weigh stock, like 1,8kg or something ?

@mortuus, the MCPCB weights itself over 0,160kg of pure copper.

When full of 18650s, the light weighs over 3,6kg.

The light weighs 3,2kg stock.

My sister was here over the weekend and she was talking to Mom about her purse, seems my sis thought Mom carried too much in her purse. 84 years old and carrying a 9 lb purse around all the time. So I guess flashaholics are wusses. :stuck_out_tongue: (What? How could I pass that up?) They went shopping and got Mom a smaller purse, parsed out the stuff Mom carried and are happy with the weight of the new one at around 5 1/2 lbs. Mom will load it back up, I’m sure of it…

yikes… thats some heavy light for sure, looks heavier then it looks it seems then. okay when its over 3kg anyways i dont see why it shouldnt support 21700 imo…

If this puppy is going to tip the scales at 8-lbs fully loaded with 18650’s then I definitely agree adding 1 even 2 more lbs to pack 21700’s inside would be well worth it.

I believe the DX80 is my heaviest light currently at 1.25kg or 2.76 lbs. (maybe my MF04 but it feels close to the DX80). I’ve gone for extended dog park visits with my DX80 which has 8x18650 with a massive aluminum PCB? (still learning… heat sink?) and after about 10 minutes I notice myself always trying to slide my hand up onto the head to distribute the very head-heavy weight better. After 30-40 minutes my forearms are definitely showing signs of a significant workout.

At almost 3x the weight here’s my humble take:
-with an abnormally large amount of weight located in the head I think 21700s would be a big improvement to help balance the beast. My MF04 is cool but it’s the most awkward light I’ve ever seen or imagined. Seriously, the only thing they could’ve done to make the MF04 more awkward would’ve been an 18350 shorty tube!
-I can’t imagine holding this with one hand for anything longer than 10-15 minutes so it would be a shoulder strap dedicated/supported light at all times for me
-With that much weight I would really push for a handle if that’s possible?

I’m seriously gobsmacked this thing is spec’ing out at 8 flippin pounds!! That’s probably heavier than my entire collection combined so far. When you’re setting records, adding some extra capacity couldn’t hurt

So has the production on the GT4 already started? If so, ignore the rest of this post :slight_smile:

If not:

- I really don’t think weight should be the deciding factor. The GT4 is not your typical 1-cell EDC, but a WOW-light and will probably be used with a shoulder strap. Even if hand operated, I’m guessing most people would allow the extra weight to prolong that WOW factor, and not having the light output dip to averages levels because the batteries are drained

- Let’s assume the light again has a FET driver like the GT70, and at Turbo the 4x XHP70.2’s all run at 10A each, that is a drain of 40A on 4S1P, or 20A on 4S2P. According to test charts, the Vf should be around 13.26v for 10A, so each cell is only responsible for 3.315v. If we assume inefficiencies bring this up to 3.4v, according to HKJ’s charts, the Samsung INR18650-30Q 3000mAh can handle 20A for about 3mins, while the Vapcell INR21700 4200mAh (or similar) can handle 20A for about 6mins. That is a 100% increase in runtime for roughly a pound in weight increase.

- Going by the same charts, calculations and assumptions, High (50% PWM | 5A*4/2 | 12.3v) would yield:
— INR18650-30Q: 14mins
— INR21700: 21mins (+50%)

- Going by the same charts, calculations and assumptions, Medium (25% PWM | 2.5A*4/2 | 11.68v) would yield:
— INR18650-30Q: 32mins
— INR21700: 46mins (+44%)

- If I have to choose between carrying additional battery cariers in my pockets or an additional bag, and having the light a bit heavier, I choose bigger battery capacity.

  • The only reason why 21700’s shouldn’t be considered, should be if the size will make the light not hand “heldable”
    (please don’t see the length of the post as a rant :slight_smile: )

:open_mouth: :person_facepalming: :open_mouth: I didn’t realize that was a common perception! lol now I feel like I need your disclaimer above permanently inserted into my signature!

hehhe yea my biggest light is the olight x9r at under2kg or so, i was using that as reference to guess the gt4… didnt imagine it can weigh that much more wow… this thing can also be used as a defense weapon, i mean swing that light with some force can break some bones :open_mouth:

This is actually my biggest issue with the 21700, it will indeed mean the light without the strap or a handle almost unbearable to use. Even with the 18650 tube and my large hands it is only comfortable to hold for a few minutes at a time.

All of these factors added together is why I have told lumintop the benefits both ways and basically left it in their hands to decide. I honestly can go either way on this one, I really have no opinion one way or the other.

Also thanks to Dale sending me a clamp meter the early prototype was pulling around 27A @ 12v with 30Q cells BUT that was with the sub-par resistance in a few areas that they are correcting for later versions. I expect 30a+ from the final version or higher with better cells. This is basically what I figured it would be when we started this. Although I think they will have to step down 1 wire size to make soldering easier (the prototype soldering overheated the driver and killed it due to how much heat it took to solder the wires), so that might counter the gains in the other areas so it is around the same.

Right now the light is just shy of 400w on turbo and hit LVP with 30Q cells at ~12 min IIRC. Although it would of gone a bit longer if not for the voltage drop, the cells were around 3.4V when I pulled them I think.

It peaked at ~88c? just laying on the table. Better then the GT70 which peaked at 92c IIRC with less then 1/3 the power.

Sadly the lack of information from lumintop means that is basically all I know and I can’t really mess with the light in case they need further testing.

Her purse would be much lighter in the rest of the world which use the metric system : 9 lbs is only 4.1 kilograms :smiling_imp: