What chemistry is inside a lion battery? How is it mixed? 
Is there an LED die size that hits a particular ālimitā for what could be used in a reflector for maximum throw? I am curious because in my casual observations it looks like if an LED die becomes large enough, a suitable reflector to accommodate it for long throw becomes too massive (e.g. going from 3ā to something like 10ā). It does look like the TIR gives a little more āwiggle roomā, but I expect thereās limits on that too.
I guess what Iām trying to get to isā¦ are there certain emitters that just arenāt suitable for maximum throw and end up more or less used in a medium range thrower host with abundant spill?
I just joined PayPal again.
So I sold the light and I got an email from them saying that my funds are on hold and that it could take up to 21 days to release them! Nowhere in this email or on their website does it say how much money is on hold.
I have no way of knowing if the guy sent me $10 or $139.
My question is what is the average amount of time for those funds to be released? I have everything set up with my bank account. You canāt seem to call PayPal that didnāt work.
Thx
Goggle āeric july paypalā.
Apparently this is something theyāre doing to hold your funds hostage on a rolling schedule if yours is a ānewā account.
Oh, at least theyāre not āfiningā you 2500bux for saying something they donāt like.
This question is so dumb itās embarrassing for me to even ask. What parts do I need to test some bare LEDs? Just a driver board and a battery/power supply capable of sourcing sufficient current? Iāve only ever played with pre-assembled lights but never messed with bare LEDs at all. A plug and play āevaluation kitā would be great, but Iāve done enough home brew electronics over the years so that if a ākitā is unavailable Iām happy enough to wire something up on a protoboard.
Just to be clear, when I say ātestā I mean run the LED for several minutes at a steady output level somewhere between 50-80% of itās rated max output.
A multimeter and a power supply, thatās all 
If itās just to check the wiring/soldering is good then a digital multimeter, though that only works for 3V LEDs, for 6V, 12Vā¦ etc then some kind of power supply, could be cells in series with a resistor to limit the current.
For more extensive testing, like characterising their output and Vf, then a power supply with which you can adjust the current, usually known as bench power supplies, then of course the tools necessary for measurements (DMM, integrating sphere/luxmetterā¦ etc)
Have a look through some of user djozzās old threadsā¦I know heās shared photos of his testing setup and the evolution thereof. Besides the power supply and shorter thicker leads, something like an old cpu cooler heatsink or similar that you can screw an mcpcp to, maybe some of the cheap white china thermal paste like GD100 or similar HY brand (fine for testingā¦actually not bad for most lights other than drying out quickly), maybe a small fan for cooling at times. Iām sure you already know that ārated max outputā/current from the manufacturers - for most white emitters - is far lower than what they can actually be driven at and far lower than the majority of our lights drive them at. If you want to do graphing there is good freebie software but I canāt remember what it isā¦should show up in other emitter test threads here.
STUPID QUESTION
Does anyone know if the head of the Foursevens Mini Turbo MKII fits and works with the battery tube of the Foursevens Quarks (16340/ 16650)?!
The best images I can get from these models (well, their recent versions) are here, but I canāt really say if they fit and work :zipper_mouth_face:
Iām probably going to get a lot of different answers from the dealer and from you guys. I guess I got to figure out which oneās best! So I bought some unprotected GA button tops Black Friday sale. Probably wonāt need them for 2 years cuz my MJ1 are doing well. The question is, can I store these two years continuous, or after 1 year should I take them out of storage charge them up and then back into storage?
Thx
^
I make a point of testing my long-term stored batteries for charge level every 6 months or so. If they start dropping down below 3.8v, I charge them back up. I donāt have very many. Most of them are laptop pulls, which are lower amperage than the high amperage (over 5A) batteries that I use for high power consumption flashlights.
In general, if youāre not using many batteries for over a yearā¦ youāre stockpiling too much. One good exception is non-rechargeable cells that you want to keep on hand for emergencies or quick stand-ins for rechargeables like AA and CR123A. The CR123A is a remarkable cell that can often keep for 10 years on a shelf before starting to degrade.
^
What level do you store them at? You mentioned dropping below 3.8 volts? I store mine on 3.55 or 3.6 volts.
I bought these because they were on sale. As I said I donāt need them probably for a year and a half or two years whenever my other batteries go bad.
Question is if thatās the case, is it okay to keep them stored for two consecutive years checking voltages but not charging them up again unless necessary.
The higher the state of charge the higher the calendar ageing, but specifically there is a threshold around 50~60% where above it degrades faster. So no, stored li-ion cells shouldnāt be topped off, in the first place they are charged from the factory at 30%, due to shipping restrictions but also because itās a good place to be since itās under that threshold while leaving quite a bit of capacity for self discharge, which is quite low with li-ion, if the cell goes into negative SOC then itās bad.
So just leave them as they are, they should be around 3.3~3.5V, you can check in one year and if you see them going towards 3.1~3V then you can get them back up to 3.5~3.6V.
First thing I do is a capacity test which Iām doing right now. After that I store them around 3.6 volts. My question was can they be stored for two continuous years or should after a year I take them and charge them and then put them back in the storage?
If theyāre going from 3.5 volts or 3.6 volts down the 3 or 3.1 in a year, something is definitely wrong with those batteries. Iāve stored them for a year and they are the exact same or 100th of a volt lower many times.
The reason I asked the question is cuz somewhere where I Googled it said you shouldnāt store them for more than a year. If you do, charge them and then you can store them again. I never really heard of that method so thatās why I inquired about it.
Iām going to keep it simple!
Iām going to leave them stored for a year check them periodically and if I donāt need to use them after a year and the voltages are fine just let them be until I do need to use them.
Thatās the same suggestion my hometown dealer gave me the one who sold me the batteries. Heās an engineer and knows pretty much about these batteries.
16340 batteries (rechargeable version of CR123A)
Whatās the āpracticalā maximum mAh available? I still have a few from olden days, when 650mAh was common. I think the highest Iāve seen is 850mAh (Vapcell). Iām suspecting this would be about the limitāafter all, there are 18350 cells as low as 900mAh, with highest around 1500mAh.
_
I imagine like thefreeman said that 3.5~3.6v is probably the ideal, in terms of minimal charge decay. Iāve found 3.8v to be fine and the cells sit at that level for a very long time. Trouble with testing this is that itās so long to find out! If you have freedom of time, do a test. Have some cells at 3.5v and a couple at 3.8v. Note the charge on the battery (little label), with date. Then do a voltage test at 4, 6, 9, and 12 months. See what happens.
FWIW, you know those old notebook hole reinforcers? They look like flat mini peppermint lifesavers? Those are great to adhere to the positive end of 18650 cells. I write the post-charge resting voltage there, so I know which cells are the best and those that are lesser (for unimportant tasks).
How should I go about getting rid of about 20 LiIon cells?
Just drop them off at Home Depot?
They are all still nearly new, not dead.
Post in the WTS forum for Canadaā¦ maybe there might be someone nearby on BLF whoād be happy to take them off your hands?
Hjeh, I was just gonna jump in with āNo prob, Iāll take āemā. 
@sunsethiker, they have higher rates of self-discharge.