IMR 18500 have just come out and im wondering what are some uses for these cells?
I mean I use IMR 16340 ALOT for lights that normally use Lico large cells...
The IMR16340 cell, since it lacks the wasted space of a PCB, and is such a small cell where a PCB displaces a large percentage of space, is actually on par capacity wise with many RCR123s. So in any case where you have a direct drive LED or incan where you can manually see the point where you need to kill the discharge to prevent over-discharge, the IMR16340 is a great replacement for an RCR123.
but other than LF IMR Lamps, what can I use IMR 18500 for? instead of liCO 18500
Depends on what results you are looking for. In a broad general sense, you can say that for 17500 cells and larger, IMR (LiMn) will have about 1/3rd less stored energy, however, will be able to safely deliver 2-3X the maximum safe discharge of the equivalent size LiCo cell.
Since the LiMn cell has lower internal resistance and no PCB to add additional resistance, some bulbs that work with protected LiCo cells are going to be closer to instaflashing on LiMn cells, especially bulbs that were already really having the **** pushed out of them...
Some people run the P91/MN11/MN16 for example, on a pair of protected 18650 cells. One can, for fun, drop down to a "2 cell" host and run any of those bulbs on a pair of IMR16340s just fine. Since the small 16340 size suffers plenty of voltage sag under the strenuous load, no new bulb related problems arise. However, replacing the protected 18650s with IMR18650s can translate to faster bulb failures, as that configuration was already hard on the lamp, the LiMn has just enough of an edge at this load to really increase the likelihood of popping the lamp.
Not only safer, but theoretically should have better cycle life under strenuous loads.
there is no PCB on IMR cells.
Defeats the purpose of low resistance high current cells. If you have an application that falls within the safe boundaries of a protected LiCo cell then the LiCo may be the better way to go. Regulated LED lights especially IMO.
I posted a thread on this question but it was shut down im told this is where to post such questions and MD your best qualified to answer anyway.
You might have a run through AWs LiMn sales threads, the original, when he released the IMR16340s, was heavy with questions of "what why where and how" and I spent the first few weeks of that sales thread helping to answer questions right in the thread.
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MD, what do you think the runtime of 2x14500 and a P90 would be, I hope more than 30 minutes.
Is it true 14500 LiCO are better than RCR16340 LiCo?
14500s usually come closer to rated capacity than RCR123s.
It would have to be a custom machined down body to be worth the smaller diameter cells, in that same length one can run 2x18500s....
Do you have a new body coming out/out already? hehe....
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You can run the P91, the FM 1794 or a WA1111, the same things you use the IMR16340s for, only with the IMR18500 the bulb will be a little brighter and run about twice as long.
I think IMR18500s are likely to blow the 1794, possibly the P91, and possibly the 1111.
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Thats my question! Why not switch to 18500 LiCo in this setup, it will run 33% longer!
(except for safety.....I see 18500 as a step down in power, but no smaller than another 18500 LiCo...)
however it will run twice as long as 16340 if you do care about using IMR for safety reasons.
Protected LiCo 18500s shouldn't really be used to power up a 1111. In the case of the 1794 and P91, it's probably preferable to deal with the risk of the LiCo cell over the IMR18500 as the LiCo will have a natural voltage sag at these loads that would be less apt to pop the bulbs. The 1794 however is still going to be high risk either way. It's just a screaming bulb that was designed to be on the bitter edge from small cells.
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I've been keeping a log of my 26500 testing. This is with stock bodies and freshly charged cells:
2x - IMR26500 (7.4 - 8.4 volts)
3854 ROP Low - GOOD
I think the low bulb was designed by pelican to have a lot more bulb life on the table as the backup bulb. We see it handle much more overdrive than the high as a result.
3854 ROP High -
(0.2 under?)
I'm actually really surprised here, so many people have run this bulb on 7AA NIMH cells... Very revealing how much voltage sag they must really be getting across the system.
3853 ROP Low - ?
3853 ROP High - ?
The high might be worth looking into, it should have an extra ~1-2V of overhead in the design over the 3864.
Philips 5761 -
(0.5 over)
Shame there isn't a really good way to drive these without all the fuss. Such a great filament shape and everything. I can run it off a pair of old Emoli cells if I rest em over night.
WA 1111 -
(0.1 over)
Poofed on my Emoli 18650s as well.... bleh
WA 1274 - GOOD (9.1 limit)
Hows the CCT look?
Osram 64250 -
(0.3 over)
Emoli 18650s poofed this one too.. bleh
Osram 64275 -
(0.3 over)
Can't say I'm surprised, the 18650s drive the **** out of it... Oh well, not the most efficient bulb anyways right-
Osram 64430 - GOOD (10.9 limit)
3x - IMR26500 (11.1 - 12.6 volts)
WA 1331 -
(0.6 over)
WA 1185 -
(0.3 over) <- safe after 24hr rest
You may find that more bulbs in that list above will survive after 24 hour cell rest. Especially the 3854H.
WA 1166 - GOOD (14.1 limit)
Comparing my results with mdocod's, 8.2 is still .3 over the 7.9 flash point for the 5761. Perhaps with more time...
Thank You for your many bulb sacrifices!
The trick is hoping that you have enough resistance in the switch, the spring, the bi-pin adapter, the contact from the bi-pin adapter to the switch tower, the contacts between cells, etc etc etc. C mags actually have lower resistance switches than D mags straight from the factory, and if it's a brand new flashlight then you have less oxidation on contacts than many people would.
Sometimes there's enough resistance sometimes not....
I was chatting with a friend on the phone, few weeks ago he was trying out his new IMR18650s in some various leefbodies and such. He was able to drive the 1111 and 1185 on the new IMR18650s without insta-flashing. Probably because he's had those flashlight bodies and switches and everything for a couple years now, so there's just enough extra resistance.
-Eric
