The There Are No Stupid Questions Thread

Not unless the lens or focus is completely f*’ed

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 it’s 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.

Something to haha “reflect” on.
Guess the robust hot spot is spot on for me. :smiling_imp:

Again, thanks for your responses! :beer:

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 ;) )

That’s not what he is talking about.

He is only talking about LVP in lights, not cells.

None of the “Big 5” li-ion manufacturers produce any cells with protection circuits or button tops at all AFAIK.

But as for expensive lights without LVP, I can’t think of any except maybe Surefire, etc. that are made to run on only CR123s?

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 “Big 5” 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 it’s 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, it’s 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 don’t have quite the same standards. PLB published some info on their 5500mah cell, but it’s 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 don’t 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. I’m 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 it’s a lot cheaper than trying to import Japanese cells to China just to resell them.

What country are you in?

Where to buy Mcpcb and led emitters wholesale or cheaper then buying say from kaidomain.com

Buying from China is cheapest, due to lower product cost and subsidized shipping. You need to buy a lot?

I typically buy from a USA store like MTN E. Costs a bit more, but faster shipping.

There are a lot of Chinese stores and their prices fluctuate. Kaidomain is definitely one of the better priced stores. Maybe someone can mention some more.

I’m new to the flashlight world but have modded a few lights the only us stores that I know of are mtelectronics that sells LEDs and mcpcbs and illumi for batteries

Illumn has PCBs and other goodies, I think. LEDSupply, too, for TIRs, etc.

Fasttech has a whole parts section for LEDs, drivers, reflectors, hosts, you name it.

I plan on purchasing a ROT66 gen II, which batteries are recommended and where can I purchase them from?

I've noticed a pattern of tiny holes in many driver boards, particularly in the traces. What's the purpose of the holes?

slmjim

Sanyo and Panasonic merged, as you noted.
Sony was sold to Murata.
Molicel is a top player as well.

Yeah, the list is quite outdated when stated this way.

Maybe we should still be talking about the “Big 5” while meaning “LG, Samsung, Sony/Murata, Sanyo/Panasonic, Molicel”?

Leddna has some MCPCBs and emitters as well.
Convoy has MCPCBs

They’re vias, plated-through holes to make a connection between the 2 sides.

Got it. Thanks!

slmjim