How about an lithium 18650 primary

TinderBox (UK)

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It would be nice if you could buy them like cr123a primaries to have on hand for an emergency, I don't ever remember seeing anybody selling them though I could be mistaken.

Some 18650 lights can handle the voltage of 2 cr123a cells but for those that cannot an 18650 sized primary would be nice.

I wonder what capacity it would have.

John
 
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smokinbasser

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Re: How about an linthium 18650 primary

What is the chemistry of a linthium battery or did you mean a lithium battery
 

StorminMatt

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Re: How about an linthium 18650 primary

But would your typical 18650 light be able to run on the lower voltage (~3.0V) of a lithium primary?
 

NoNotAgain

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If you were to be able to purchase primary lithium 18650 batteries, they'd probably sell like ice cubes to Eskimo's.

Single price of a CR123 is over $6 retail. A 18650 would probably be over $12.

Then you'd have to establish a standard of what the voltage should be, 3.0 volts or 4.2 volts and a manufacturer to produce products that will operate on said voltage.
 

archimedes

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If you have an 18650 powered flashlight which can specifically ( and safely ! ) run on the lower voltage ( ~3V ) of a lithium primary cell, it is relatively easy to use a spacer / sleeve for emergency use of a single CR123A .... Yes, capacity is relatively low ( ~ 1500mAh) , but that flashlight will also need be more limited in terms of current draw and output ( for safety )

Most flashlights designed to run on 4.2V will not, however, run well (or at all) on 3.0V

:caution: and high-powered lights may attempt to draw too much current from a lithium primary, which can cause dangerous overheating :caution:

Also, perhaps worth noting, is the existence of the CRAA / CR14505 (3V, 1500 mAh) lithium primary cell.
 
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CuriousOne

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There are 18650 primaries, made by Tadiran and Saft, but neither price, or specs are attractive :)
 

cdm-dude

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The long shelf life of primary lithiums makes them perfect for "emergency/backup". I love my 18650 li-ions but I totally get what the OP is driving at. If there were "good" primary lithium "18650" cells that had the nominal voltage of +/- 4V and a shelf life of 15+ years, I'd be willing to shell out 20 bucks plus on each such cell.. but then I would probably only buy a dozen... One or two I would keep handy while the rest would go into the freezer... and that would be the end of it... I would not need to buy any more of them primaries, probably ever... So yeah.... "ice cubes to Eskimos", that sounds about right.

Fortunately, the driver in my NC MH20GT is beyond awesome. The unit can run off almost anything you can throw at it. It works great with two CR123's (primaries). I had to buy the holder for them separately but it all worked out. I actually got me two of those holders, one for each bag I carry with me. With two CR123's in each one them holders, I always have at least 1 "backup" for that flashlight, plus, CR123 aren't as rare as the 18650's. No matter where I am, there's a good chance of finding suitable batteries for that flashlight of mine.

So, I guess, my advice is to only buy 18650 flashlights that support voltages of 6.5V, because that's what you'll get from connecting two of them CR123's in series. *The MH20GT can go even higher than that, not sure if that's harmful to the unit though.
I haven't tried it myself, but there's a good chance the NC MH20GT can run off a single CR123. I would need to get me a "dummy cell" for that or some sort of spacer, or I could just hotwire it for the test... too lazy..
*In my previous tests, however, the flashlight stops working when the battery voltage drops to 2.7V. Or maybe that's the low-voltage protection in the cell kicking in. At any rate, at those voltages the light output is very weak but I guess, a single 3V CR123 could be infinitely better than just the dead 18650 battery. If someone could test this theory, it'd be great! And if anyone could point me in the direction of a CR123 dummy cell, that too would be awesome!
 
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