I was browsing around at manny font, and saw something I'd not seen before. Did a quick search here and couldn't find any references. There are references to other MarsFire products here ATM (including a thread about yet another *Fire name!), but discussing batteries, throwers and the name [snort].
Anyone know anything about this beyond the obvious description?
They claims "4500 lumens"(!).
I was going to metaphorically cough. But 4500L / 6 LED's = 750 Lumens per LED, which is conceivably achievable here (though probably not Out The Front). Per Digi-Key, an XM-L produces 750 lumens at 2 amperes, at an efficiency rate of 110 lumens per watt. [Peak efficiency is 160 L/W, at 0.35A.] Honest stats, or something close to it??? (Hey, at least they didn't go claiming the "manufacturer rated" maximum, times 6 LEDs.) Went a little further mathematically. I don't know the voltage they assume at 2A, but I assume a lower voltage than a lithium battery. Assuming 3.3V x 2A (someone will correct me), I timidly calculate 6.6 watts, x 6 = 39.6 or say 40 watts.
40 watts / 3 cells = 13.2 watts per cell. Not bad, actually, not bad at all. Even 2A at 4 volts would be 8 watts per LED, x 6 = 48 watts total, or 16 watts per cell (4 amps at 4 volts). Of course there is driver inefficiency, but 4 amps, that's eminently doable for a quality 26650 cell. Hm. Real-world draw is another animal altogether, but safely drawing 4.5 amps per 26650 cell, could be actually close to that number. Even 4000 lumens would be impressive! Remember when 120 lumens was impressive?
Could it be here that we have a light capable of doing four thousand and a half lumens, for under $80? Anyone have estimates of the DRY 4-mode (which is 3 XM-L's)?
It's the same drill for anything above 3 x XM-L over and over again, the driver is the deciding factor which is sometimes further limited by the batteries.
Interesting. Well, with fairness, that link is almost double the price (though includes 3 batteries and a charger). [and, it's aliexpress.] Yeah, definitely the full 'manufacturer rated' specs there and no name. I don't know if it was manafont or the manufacturer who rated the MarsFire one more realistically, but, it beats the wild claim of 7000L. I just haven't seen a 6 XM-L light on the market before. So, while maybe ho-hum in some minds, I think it is technically new. I am not a multi-LED owner, but considering becoming one. I passed on the 5 XR-E DX models awhile back... but maybe it's time. That thing is a baton! But I mean, a DRY 3-LED or something similar is going to cost about as much... so the obvious question is... which puts out more light? My guess is at least this could do it for longer..
EDIT... Thanks 2100, for the post, hadn't seen that. 7 XML's, well that is the record then, in terms of something you could actually buy. Yeah, really underdriven LED's is always the concern, so, yeah, you're right, it would logically all come down to the driver (and heatsinking). 7 begins to look ridiculous. Maybe they decided to back off, LOL.
Sorry if this is too off topic... just say so and I will delete this comment, no harm done.
I just got a set of 26650 LiNiCoMn cells form BS and they very comfortably did 5.45A in a direct drive single cell XML light.
3.6V x 3 =10.8V (3S)
10.8V x 5.45A = 59W for 3S arrangement... So these cells at least NEW out of the box look like they are very capable of delivering a lot of power. So the big unknown in these lights is the driver and thermal performance of the host.
The one I am looking at is the skyray 856. (its only a 3-XML so it should be more stable in terms of cooling).
Yes Kramer, the KK 26650s can comfortably deliver ~ 20W per cell, say that's 6A. Panny NCR18650A could also, but i did say comfortably. If the light takes 3 x 26650s that'd be 60 watts.
You could drive 10 XM-Ls really efficiently with 60 watts and do a lot of lumens with very manageable heat output in a big host like 100mm head diameter. These latest muli XM-L heads are already doing 75mm, up from the 60mm class like the TR-J12 (62mm I think).
Should i get it? I could squeeze 2 x DRY drivers in there (I have lots of them Turbo drivers) and it takes 3S input. Wire 3 of them to one driver, 3 of them to the other.
I would be looking at 5000 lumens OTF, 98% confirmed. Fun for exactly 1 minute gunning.
7 or 9 XM-Ls won't work for this. Don't think i can squeeze 3 drivers in there.
Just saw that there is apparently a 2-cell option for this too. Comes with an extender for 3 cells.
Kramer, thanks for the info. I have a pair of 26650's, but haven't had much use for them yet. I like the term "comfortably". I know what you mean, at least for my 18650 cells, just unfamiliar with 26650's 'comfort zone'; that helps.
I gotta admit... 2 DRY drivers in there, 6 LED's.................. wow. LOL. You could sell it like a CPFer ;) .
Just a personal opinion... I think theres a LOT of good uses and applications for a light like this. If in fact it does intentionally under drive the LEDs, in favor of cool running XML efficiency... thats a major thumbs up in my book. So even though it may not meet its published lumen specs, the major advantage to that is a long running wall of area flood that doesn't dim from thermal deficiency, may not over-tax the cells, and you'll be able to comfortably hold it after a ~20 minute constant ON cycle.
Remember too that the 26650 cell performance ceiling is largely un-mapped at this point. Lots of www retailers sell them... but theres just not much hard data, user feedback and measurement analysis to evaluate their capabilities (as compared to the 18650 size).
Isn't the Trustfire TR-J12 still a better choice due to it being a well made proven design? It's also just about as bright as the DRY too. Just curious to what you think.
generally, I prefer the mode you describe, and in addition - a low (or moon low depending on the light) and a 'so ridiculously bright that even a small child knows it will probably explode if you run it too long' type of mode...
You can do it other way, more safe: 2S3P setup with a 7-8amp classic driver it might have. 2,3-2,5 per led, this is 650 per led, so almost 4000 OTF might be feasible for one hour with three 26650.
