[Solved] Source for "button" or "flat" top 18650 Li-Ion

@inq I am not 100% positive about this, but my understanding is that quality Lithium batteries are sealed, and the factory recommendation is to put them in water if they start to overheat.

My interpretation of that is:

Don't cover the posts for a long time, but as long as the seals are intact a couple of minutes won't hurt

When I lived on a lake, I often saw neighbour's small boats get full of water from a rainstorm, especially if they were away for a long weekend or more. On a few occasions, I went and pumped them out, and the battery that was a sealed lead acid type survived just fine and they were submerged sometimes for days.

If in doubt, just ask the manufacturer. Or perhaps WILL PROWSE

Posted by: @zander

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When I lived on a lake, I often saw neighbour's small boats get full of water from a rainstorm, especially if they were away for a long weekend or more. On a few occasions, I went and pumped them out, and the battery that was a sealed lead acid type survived just fine and they were submerged sometimes for days.

If in doubt, just ask the manufacturer. Or perhaps WILL PROWSE

Well... lead-acid is a completely different beast and water only makes them more stable.  Lithium on the other hand does not mix with water well.  And yes... for the 90% condition, they're supposed to be sealed.  However for someone being off-shore, hours from land and a battery is going critical for whatever reason, one must assume it might be compromised/damaged.  Water ingress might occur and make a bad situation like water coming into the boat even more life threatening if a lithium fire breaks out.  It is my understanding that those start and even maintain UNDER water.

But we diverge.  For LiIon 19650 in our little electronic projects... I'm really far less worried about such hazzards.

Hi @inq & Ron @zander,

    Sorry .. old age and writing at silly o'clock means I make stupid, embarassing mistakes ... I did mean phosphate not sulphate ... ie LiFePO4. I probably should write it offline and check a couple of days later, before posting, as I am really bad at spotting my own goofs, but that is tricky in a forum situation.

As for water immersion .. then you are right, lithium, as an the element, does react pretty vigourously with water .. but rechargeable lithium based cells under discussion, have little, if any lithium in that form .. the clue is in the name Lithium-ion ... ie lithium chemically attached to something. Furthermore, the water immersion is based on the cell still being intact, just overheating. If it is past that stage and on fire, emitting gases, etc. retreat as fast as you can, while you can! The point is, if you can cool them quickly enough, you can reduce the chance that it goes into the full firework display mode.

e.g. https://www.cnet.com/tech/mobile/what-to-do-phone-laptop-battery-swell-bulge-hiss-fire/

If you remember another chemistry lesson, you might recall sodium is also pretty excited to find water ... but sodium chloride is the white stuff you might put on your crisps/chips/fries .. and I have yet to see them burst into flames. Similarly with potassium and potassium chloride.

There are also 'lithium' batteries, which do contain lithium, but you are only like to find them as 'non-rechargeable' type. I suspect the small coin cells are of this type, which are hazardous, though their size limits the amount of lithium contained. I think some larger cells, again for 1-use applications have also been produced, but I am not aware of them being commonly found in domestic situations. Things like automatic locator radio transmitters for boats and aircraft might use them. Clearly, these require different treatment!

One of the potential hazards with old lithium-ion batteries is attempting to recharge them, might result in electrolytically producing lithium ... like splitting water into hydrogen and oxygen. How often this is a contributing factor to incidents is unclear .. I cynically suspect it is less common than other failure mechanisms that can affect new cells as well as old ones, but have no proof.

Much of the risk from lithium-ion batteries come from the other ingredients, many of which are also highly-flammable, plus they usually contain sources of oxygen. Regrettably, manufacturers rarely disclose the construction and contents of their cells (beyond the bare minimum), so it is always a bit of a gamble.

From what I recall of my previous reading, punching nails into lithium-ion cells, whilst definitely not "an experiment to try at home", is not generally the worst scenario. Whilst the puncture may result in some very unpleasant results, the puncture allows the gases to escape. If the cell doesn't have a release mechanism, then if it overheats, it can become a grenade ... hence cells with a metal casing (e.g cylindrical cells) should have a pressure release mechanism that will rupture relatively safely if the pressure starts to build up.

Stay safe .... it is also fair to point out that the incidence of cells catastropically failing is fairly small.

 Best wishes, Dave

@davee Now I know I am having some sort of a nightmare, yesterday I found a mistake by one of my heroes Dennis (@inq), and today, another in the form of Preacher Dave (@davee). All that is left is for the erudite Will (@will) to suddenly develop feet of clay.

I hope I wake up soon; this isn't fun.

Hi Ron @zander,

   I have been making mistakes all my life ... but hopefully also got a few things right, if not at the first attempt, then eventually.

A quick Google suggested ...

@zander 

IMHO, the only people who have never made a mistake are the ones who have never made anything.

@will Very true, I certainly have made more than my share but as long as I learn something then that is ok.

Posted by: @davee

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If you remember another chemistry lesson, you might recall sodium is also pretty excited to find water ... but sodium chloride is the white stuff you might put on your crisps/chips/fries .. and I have yet to see them burst into flames. Similarly with potassium and potassium chloride.

I was a Physics guy... after Entropy in Chemistry, I checked out! 🤣 

Posted by: @zander

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@davee Now I know I am having some sort of a nightmare, yesterday I found a mistake by one of my heroes Dennis (@inq), and today, another in the form of Preacher Dave (@davee). All that is left is for the erudite Will (@will) to suddenly develop feet of clay.

I hope I wake up soon; this isn't fun.

And next...

Posted by: @davee

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If you remember another chemistry lesson,

The single most important thing I learned in Chemistry classes was "never lick the spoon" !

Hi @inq,

  Re: I was a Physics guy... after Entropy in Chemistry, I checked out! 🤣

  Curiously, I did my best to do some Physics, Electronics and touch of Computing, whilst also staying in a Chemistry environment, for quite a time ... but apart from a few perverse puns, I can't recall ever discussing entropy beyond the definition based requirements of the course.

Perhaps my life was just too disorganised & chaotic?

Best wishes, Dave