Yes, that is what I supposed. I wanted to try the SST20 and 219C 5000K together to increase rosiness and get a 4500K tint. They would get around 3 - 5A per led. Do you think the 219C would draw more current than is good for it?
So I might need to mix LH351D and SST20, throwy in the center and floody outside, not bad either.
It just seem sensible feature to me extra safety but I understand you shouldnât just rely on it. I was just thinking why they wouldnât include it, i would not use one without lvp when using Li-ion Batteries even protected ones.
Most âzoomieâ designs waste a lot of light when the LED is highly focused because there is no reflector or TIR optic to capture what is shone to the sides.
Both of the latter capture almost all of the light an emitter produces. I would say âphoton densityâ sounds like intensity/candela though, and zoomies can actually still blow away reflector or TIR lights of the same bezel/head size.
Like BurningPlayd0h said, itâs about optical efficiency. Typical zoomie efficiency between wide angle and narrow angle can be a factor of 3. It might put out 900 lumen in wide mode, but only 300 lumen in narrow mode. It has terrible efficiency but it can still be pretty intense and throw a long distance.
Did we answer your question, because Iâm not sure what you were asking about.
To my eyes, when focused on a distant object, the convex lens throws well, and the
Object can be seen clearly, but it seems like a flat projection while a reflectorâs
Light seem more robust, and illuminates with what seems like a more intense beam.
Is it possible a deep reflector throws most of the photons into the projected beam, while the
Zoomie is less efficient in doing so. With losses. In arcs of artifacts
Reflectors tend to put about 50% of OTF light into the hot spot. The other 50% goes into the spill.
Zoomies put maybe 30% of the light into the narrow focused beam. Something like that. If itâs focused exactly, they basically project an image of the led die. There is no coma or corona around the edge like with a reflector hot spot.
Maybe the perfectly straight columns of light from the projector/convex lens gives that flat appearance. The reflectors columns of light are not perfectly straight. It tends to blend the beams of light together more for a smoother hot spot. IDK, just guessing.
Adding a protection on batteries is not free ! It costs some money, some space and even adds to self discharge and internal resistance so it make sense to add it only when it is really required.
I don't know who you mean exactly with "more expensive brands" but imho the big names like Sony, Sanyo, LG or Samsung don't include it because most of the batteries they sell are used in packs (think electric vehicles, power tools, laptop PC, ...) witch use a battery management system that already take care of lvp and several other things.
The market for batteries with individual protection is a very small one compared to what they are used to deal with and they seem to prefer letting smaller companies taking care of that (and buying their unprotected batteries ;) )
I would have a question. If my understanding of the Li Ion cells manufacturing is correct, there is only handful of original OEM manufacturers like Samsung, LG, etc. Most cells on the market are rewrapped OEMs from these companies. Could someone fill me in on who are the manufacturers behind various Chinese brands of 18650 and 21700 cells then? Brands like Golisi, Liitokala, Lishen, Shockli and so. Do they run their own OEM factories beside the well known big manufacturers?
The âBig 5â are Japanese manufacturers. LG, Samsung, Sony, Sanyo and Panasonic. Sanyo and Panasonic merged a few years ago so you sometimes see the same cell under either of those names.
There are a whole host of China based battery manufacturers, but they focus on wholesale production. They sell to other companies who focus on branding and marketing. Companies like Golisi, LiitoKala, Shockli, Keeppower, Efest, Orbtronic, Vapcell, etc⌠buy from various sources. Some come from the Big 5 and some come from unknown companies. This is why itâs important to know whats under the wrapper.
The only Chinese company I know of is Power Long Battery or PLB. They make the great 5500mah cell that measures about 5750mah and can do 20A continuous. It is resold by Shockli, Keeppower and Vapcell.
Most of these Chinese resellers will not tell you the company they buy their cells from. They try to keep it a secret. Sometimes they even switch the cells and keep the same wrapper.
Oh yeah, itâs quite known that the Big 5 have the best quality cells, do the highest testing and provide data sheets for their cells. The other brands donât have quite the same standards. PLB published some info on their 5500mah cell, but itâs hard to find. Good luck finding data sheets for the others. Some are out there. Typically you can rely on tests by Mooch or HKJ.
Thanks for confirming my thoughts. So better sticking with big 5 OEM, than playing lottery with unknown manufacturers under different wrappers. Too bad most of my sources dont sell the OEMs and European stores charge ridiculous shipping. Are there any reliable stores at Ali, that sell original 21700s (like 50E, 40T etc.)? I found some but the reviews are mixed.
Aliexpress is like Ebay, a bunch of random stores that sell through the same website so you donât really know what stores are legit and which are crooks. Some are known good and some you take a chance with. Lishen makes a good 4000mah 21700 and it can be found at Banggood under the LiitoKala brand. Iâm not sure what cell is used for the LiitoKala 5000mah 21700.
Most of the Chinese stores like Aliexpress, Gearbest and Banggood sell the Chinese brand batteries. I guess itâs a lot cheaper than trying to import Japanese cells to China just to resell them.