But then focused to a 80 degree almost uniform beam it’s still impressive (at least we think so) - look at video.
We can squeeze more lumens, but we want that flashlight to be usable. Not a one second toy.
The XM-L2 U3 is pretty expensive and among the most powerful leds in 5050 size, so all is good with the description.
But for perspective, the Cree XP-L/XP-L2 (3535 size, so smaller) is just as powerful, Nichia 219C/319C comes close, and now there is the Luminus SST40 which also has about the same specs. The Cree XHP50/XHP50.2 will unusable for your purpose because it is a 6V led (quad die), but strictly spoken it is a (way) more powerful 5050-size led than the XM-L2.
Btw, it looks like a nice key chain light, and a bit brighter than comparable lights that are on the market (the several nice DQG key chain lights).
I could be wrong but I think this kind of discharge is too much for a 10180, unless it’s an IMR and I am not aware of IMR in this size. Your circuit also needs a cut-off around 3v because the cell will be over-discharged and will die after a full discharge. Does the circuit monitors the voltage ?
Yes, it’s too much. And it will have only 50% of capacitance after 20 cycles of disharge at 800 ma.
But we can’t avoid that if we have a task to build keychain flashlight with such brightness.
We have a cut-off at 3.2V
I don’t want to bash you, really.
But advertising fake lumens is a poor strategy…
I suggest that you advertise the right lumen (350 if I’m not mistaken) and use the ANSI throw distance given by the candela calculation.
You’ll be able to advertise maybe 70m of throw, which is still impressive to most customers and don’t make you a blatant liar…
I saw that you used KS to make a reputation, not for fund raising…so make it right, bad reputation is easy
___Yes, it’s too much. And it will have only 50% of capacitance after 20 cycles of disharge at 800 ma. But we can’t avoid that if we have a task to build keychain flashlight with such brightness. We have a cut-off at 3.2V___
That's an acceptable trade-off for such a small sized rocket. As long as it does not completely discharge, very few folks would run this light on the highest setting for 4-5 minutes so I don't see it at as cell killer. Very interesting light and I'm quite sure I would buy it !
X3, I’ll measure lumens once more on professional equipment. Now I think that we exceeded 800 ma when battery voltage was above 4V (we charge it till 4.2V) and first 30 second it was really 550 and then fade a bit.