18650 gets super hot when charging

In plain English, Im calling bullshit on your part. If this was your first day on the forum, Id be more than happy to answer your questions. But in all honesty, you’ve demonstrated that you ask the same questions over and over across several threads and then enjoy being argumentative when given answers. Im asking you to stop this now please. You also know that a simple search will answer 99% of your questions in far greater detail than here. Go find attention somewhere else and stop that crap! Thank you!

Call whatever you wish, i don’t mean to waste your time so i apologize for starting this thread

No smart or hobby charger capable of reading internal resistance? If not, it sounds like it's time to get one. It won't warn you of all dangers, but it just might tell you what's going on, and if you regularly test and log your batteries in the future it will tell you when to discard batteries before they become too dangerous.

I’m like Adam Savage, i love consistent data, so i will have to get one, and now i can’t resist uploading this clip

Recycle the cell Bortie
/thread

I agree with the previous advice that it's not a big deal, but I think it's pretty obvious that 'not a big deal' means that when a cell starts letting you know it's unhappy, stop using it and dispose of it properly. See? Not a big deal.

However... it's definitely no longer not a big deal if you continue trying to use it and fix it and see if it might get better on its own one of these days... get rid of it and it no longer has the potential to go from not a big deal to oh shit my house just burned down.

Its getting recycled, i am just going to drain it to nothing first

good laptop pulls are just too easy to get to bother with potentially iffy/dangerous cells.esp since this is a known pattern failure mode with these.

so far the battery measures 3V, i am still draining it, i want to see at what voltage the XM-L will no longer light

I had a similar laptop pull that was getting hot when charged, but it measured only 150milliOhms resistance. I did discharge it and it had around 1000mAh. No problem dumping that icr samsung.

i had one laptop pull that did the same thing. it got almost to hot to touch while charging. would be best to launch that one out of a potato gun into orbit.

Id like to suggest it needs to be disposed of improperly. The only question is what that entails. Cheap microwave and a long extension cable? A nail and ambulance?

Obviously there will be a camera.

i would probably either use a couple wires taped to the contacts and use a 100-foot extension cord, place it far away in a field and plug it into a 240 volt socket,
or use a 100 foot long string attached to a trigger of an old 12-guage shotgun clamped to a stump, and the battery resting in front of a Slug in the chamber. ( pointed in a safe direction. :stuck_out_tongue:

Well so far nothing so elaborate, i’ve left it on low voltage warning for a couple hours, it refuses to completely die, i got it down to 2.79V and the LED still barely lights so i will continue draining

> can it still vent and flame under 3V if i fully drain it in the light before disposal?

Yes.

For those new to this much-discussed subject, the problem is that by the time the cell isn’t working well, beyond the point where the chemistry can be recharged, dendritic crystals grow very slowly in the chemistry:

“The electrodeposition of lithium metal – which is an unwanted incident in lithium ion systems – often results in fine filaments or moss, called dendritic lithium, which leads to strong capacity fading and the danger of internal short circuiting.”

Journal of Power Sources
Volume 261, 1 September 2014, Pages 112–119
Mechanisms of dendritic growth investigated by in situ light microscopy during electrodeposition and dissolution of lithium
http://www.sciencedirect.com/science/article/pii/S0378775314003425
Picture: http://ars.els-cdn.com/content/image/1-s2.0-S0378775314003425-fx1.jpg

Once a crystal grows big enough and pierces the membrane separating the reactant chemicals — that’s an internal short circuit — those volatile, flammable chemicals used mix. They mix rapidly.
And get hot, very hot, and vent gas and oxygen so your standard fire extinguisher or water does no good.

You know this.

Every time I look this up, there’s a new study. You know how to look this stuff up.
For example:

Lithium-Ion Batteries Hazard and Use Assessment
SpringerBriefs in Fire 2011, pp 85-104
Lithium-Ion Fire Hazard Assessment

Lithium-Ion Batteries Hazard and Use Assessment
SpringerBriefs in Fire 2011, pp 105-114
Lithium-Ion Fire Hazard Gap Analysis

I’m assuming the original guy here is chain-yanking or doing a graduate thesis on public health and safety or looking for evidence of bad advice for a lawsuit or proposed regulation.

So I’m answering in a precautionary way.

Think about it.

I can only read the abstracts, but none say a fully discharged battery can ignite