You cannot safely pull the required current even from IMR 16340s. It possibly will work for a while with extremely scrupulous cell balancing. But not a good idea. You are right on the boundaries and any mistake could lead to a nasty explosion - you can make IMR cells explode if you are cruel enough. Check CPF for the TK Monster explosion thread. Those were IMR cells.
You are aware that every 16340 cell is grossly overrated for capacity. I'd guess at those discharge rates you would be lucky to get 200mAh out of them. You are talking a 30W device at 9A. At 5A you would probably do better with an SST-50
When (if?) flashlightnews.net comes back up there is a lot of detailed design information for the Varapower lights and choices for power control.
Forget about the 16340's, you need a 18650 IMR cell to provide that a high current.
DD with a resistored low mode is easy to implement and does not need you to build an AMC sandwich or buy an overly expensive pre-built regulator. There are also some PWM based boards that can tolerate lots of current but they tend to not work so well run on a single lithium cell.
well the reason i ask is the sst-90 (on star) is only 50 bux (yea i know, ONLY lmfao) on ebay.
that seems like a decent price, but the sst-50 is 40! thats a rip to me. considering the p7 is only 15 or less
if i do 18650s, i can't see one being able to provide more than 4 or 5 amps. i was hoping to get more. in that case i would need a 2 or 3 sized 18650 and that would be ALOT bigger than i was hoping for.
that would be way too expensive of a case, it would be like the ultrafire sst-50 thats like 170 bux, might as well go HID then!!!!
(which is another project i have yet to start, have extra HID bulbs and ballasts from cars lol)
is it possible that an IMR 18650 can provide the current necessary???
and why dont they make this LED like the MC-E, where i can run it in series for a higher voltage (tricky, but i have seen it done) with less amperage.
then i would consider a drive with the 16340s a more viable option. (8.4Vf at 4 amps vs 3.6Vf at 9 amps.)
OH YEA! speaking of IMR 18650 (those are the AW ones im assuming.) i was looking at their newest one on lighthound.
turns out its a panasonic cell with their protection circuit. if im building a circuit that is designed to cut off at the designated circuit, would i be better saving the 20 buck difference for two batteries without protection from AW?
AW charges 19 bux EACH and from ebay they are (not protected of course) two for 23
im replacing my trustfire flames (u know, the version thats NOT overrated lol, yet i have some that cant push over 1.5 amps, cheapo quality) and want something that will put down the power, but some flashlights DONT need it to be protected
and my soshine charger DOES shut off charging when it detects its charged!
AW's IMR18650 cells can deliver 16A continuously so they can power a SST-90 without venting, they can be found here: AW IMR
You can find SST-50's on stars at shiningbeam and KD for around $28, still more expensive than MC-E or P7 though...
If you do a single cell DD IMR18650 light then you don't need protection circuit and will not have any balancing issues etc. Multi IMR16340 is more hazardous and tedious to implement since you need to keep the cells balanced, you also need some kind of discharge protection and a step down regulator.
to me my time in this is just for fun. so that cost is $0.01 an hour lol
Yes, I realize the fun aspect. My opinion is that it's "fun" to play around with them, put them up against light meter, little tweaks, etc. I'm a major cheap-ass and don't want to spend good money on fun. I'd probably roll a wheel with a stick before I spend $100 on bar tabs.
But once you start circuit design, like serious bidness with equations and stuff, it's more akin to work. Then spending $ on parts is not a big deal.