Glad I took the time to look into this forum.

fuyume

Enlightened
Joined
Jun 25, 2021
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323
I'm very glad tonight that I took the time to examine this forum, because I honestly had no idea of the level of risk involved in using lithium primary cells, particularly so in multi-cell series configurations. I use a Bushnell 20154 2xCR123A flashlight that I bought on a whim on clearance at Walmart a few years ago, and I use it infrequently around the house as a utility flashlight.

I just disassembled it and took the Duracell batteries out and will permanently discontinue the use of this flashlight. I had stopped using my Leatherman Serac S3 because of the expense of the batteries, so the good news is now I have a battery for it and a spare that each probably have a decent amount of life left in them. But first, the next thing I'm going to do is grab a multimeter and read the voltage of them.

I never really liked that flashlight, because it turns on in Hi mode and has very sharply machined edges that make it very uncomfortable to hold, but I was honestly thinking of buying a Fenix E20 v2.0 to use around the house and putting Energizer L91s in it, anyway, as I had already decided to standardise on AAs.

I think if I do get an E20, I will stick to alkalines, and henceforth only ever use lithiums in single-cell devices. And when the two remaining CR123As finally go dead, I will pass my Serac S3 onto someone else who can better afford the batteries.

I've never had a lithium battery of any kind totally fail, but I have seen one of my cell phone and one of my laptop batteries bulge. I disposed of the cell phone battery, but the laptop battery is still somewhere in the house. But now I know I definitely do not ever want to experience a catastrophic failure of a flashlight battery.
 
I'm very glad tonight that I took the time to examine this forum, because I.......
Me too. I studied this forum for months before cutting loose and began snapping up high performance flashlights. I have at least six lights that use eight 18650 unprotected lithium ion cells, and two lights that use eight 21700 cells, and three lights that use three 21700 cells, and a bunch of lights that use four 18650 cells.

But, I read the forum first.
 
Haha, it turns out the two batteries read 2.824 V and 2.844 V. Looks like they were probably safe enough, but I'm still not using them anymore. The 2.824 V cell won't even light up the Serac S3, but the 2.844 V cell does. I suppose it won't run for long, though. Into the trash they go.
 
Haha, it turns out the two batteries read 2.824 V and 2.844 V. Looks like they were probably safe enough, but I'm still not using them anymore. The 2.824 V cell won't even light up the Serac S3, but the 2.844 V cell does. I suppose it won't run for long, though. Into the trash they go.

Lithium Primary and Li-Ion are two completely different cell chemistries. One is good for low temperature operation and one is rechargeable. Can Li Primaries still have issues? Sure, of course they can. But they are at least as safe as any high density power supply. You could use a single 16650 in place of the pair of primaries or even an 18650 if the tube is large enough. Anyway, I don't believe you had anything to worry about.
 
Seems most of the primaries that go 'pop' do it toward end of life... so not much stored energy. Rechargeable lithium cells are another matter....

With improvements in emitters... not as much need for multiple primary cells (or secondary) for the bulk of the lights out there.
 
Lithium Primary and Li-Ion are two completely different cell chemistries. One is good for low temperature operation and one is rechargeable. Can Li Primaries still have issues? Sure, of course they can. But they are at least as safe as any high density power supply. You could use a single 16650 in place of the pair of primaries or even an 18650 if the tube is large enough. Anyway, I don't believe you had anything to worry about.

I am perfectly well aware of the difference. CR123A primary cells can and do explode, and there is a particular risk with multi-cell series configurations. Is it a rare occurrence? Yes. Is it catastrophic in those rare instances? Often.
 
Seems most of the primaries that go 'pop' do it toward end of life... so not much stored energy. Rechargeable lithium cells are another matter....

With improvements in emitters... not as much need for multiple primary cells (or secondary) for the bulk of the lights out there.

The ones I have are, in fact, near the end of their life, at a little more than 2.8 V. I didn't realise they were so low, because the flashlight was still bright enough to be used as a utility light around the house.
 
examples please...

CR123A primary cells can and do explode, and there is a particular risk with multi-cell series configurations. Is it a rare occurrence? Yes. Is it catastrophic in those rare instances? Often.
 
examples please...

I don't follow cell failures religiously, but I have seen more than one thread on CPF detailing (with pictures) primary 123 failures resulting in cell 'disassembly'. The real 'pop' comes from this happening inside a more or less airtight metal tube.
 
well hells bells, i'd better sell my nos surefire 9p then?!?

thanks, jim

I don't follow cell failures religiously, but I have seen more than one thread on CPF detailing (with pictures) primary 123 failures resulting in cell 'disassembly'. The real 'pop' comes from this happening inside a more or less airtight metal tube.
 
Yup better Get rid of that. Send me a PM and I will give you my address. I will take this terrible burden from you.
Seriously though OP. I Wouldn't just throw my flashlight away and tear because you read something on the internet. I've been using multiple primary lights for years and never an issue. Just don't put a new cell in a dead cell together in the same light. And don't try to recharge them. And you'll be fine
 
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