Damaged battery? Is it safe to use?

Chatika_vas_Paus · 2019-05-12T17:00:01.000Z

I’ve disassembled the battery pack for parts today. I wanted to break off the plate that were welded. Unfortunately, holes were created in the battery cathode, and then something was hissing.
I have not yet attached any energy receiver to it. I only checked the voltage, which is now 3.9V in all of them.
Is the use of such a battery safe now?

BlueSwordM · 2019-05-12T17:22:05.000Z

No, it’s not safe.

If pressure builds up for any reason, you’ll have organic solvents and some HF acid(dangerous, and toxic to bones), so I would just tape it and take it to a recycler, and discharging it using a resistor.

zak.wilson · 2019-05-12T17:21:26.000Z

BlueSwordM:

HF acid(not dangerous, but toxic to bones)

Those two statements seem contradictory.

HF is extremely dangerous. Contact or inhalation can cause chemical burns, nerve damage (not just at the contact site), and bone damage. More on HF

BlueSwordM · 2019-05-12T17:37:10.000Z

See, the thing is that HF is not a very corrosive gas, compared to Cl- anyway.
It’s more dangerous in its liquid form, but it is dissolved in the form of a gas in the liquid electrolyte.
The solvent are more dangerous anyway in a lithium ion cell.

The main problem in its volatile form is that it very easily interacts with calcium supplies to form a calcium fluoride salt, insoluble in water.
Can cause damage to the nervous system, toxic to bones, and can lead to cardiac arrests.

hank · 2019-05-12T19:09:03.000Z

HF is formed by chemical reaction in a lithium-ion battery fire.

https://www.nature.com/articles/s41598-017-09784-z

Lithium-ion battery fires generate intense heat and considerable amounts of gas and smoke. Although the emission of toxic gases can be a larger threat than the heat, the knowledge of such emissions is limited. This paper presents quantitative measurements of heat release and fluoride gas emissions during battery fires for seven different types of commercial lithium-ion batteries. The results have been validated using two independent measurement techniques and show that large amounts of hydrogen fluoride (HF) may be generated, ranging between 20 and 200 mg/Wh of nominal battery energy capacity. In addition, 15–22 mg/Wh of another potentially toxic gas, phosphoryl fluoride (POF3), was measured in some of the fire tests. Gas emissions when using water mist as extinguishing agent were also investigated. Fluoride gas emission can pose a serious toxic threat and the results are crucial findings for risk assessment and management, especially for large Li-ion battery packs.

Hydrogen fluoride does damage but not immediately. Damage may take days to appear.

Contact medical help if you breathe anything leaking from a burning li-ion cell.

https://www.google.com/search?client=firefox-b-1-d&q=hydrogen+fluoride+delayed+damage

Hydrogen fluoride - National Library of Medicine HSDB Database
https://toxnet.nlm.nih.gov/

Toxicity may be delayed by up to 4 days after dilute exposures.

Remember the key thing about a lithium-ion fire: don’t inhale!

fluke · 2019-05-12T19:07:09.000Z

I had a 26350 leak liquid content all over my hands, smelt nice as well

Chatika_vas_Paus · 2019-05-12T19:42:21.000Z

Cholera. I did not know it could be that dangerous.
While I break off the plate, only a slight hiss was heard. There was no smoke or any unpleasant smell. I guess it is not so bad. Nevertheless, I put out eight batteries behind the door. Tomorrow I will try to somehow discharge them and dispose of them.

BlueSwordM · 2019-05-12T19:50:17.000Z

The problem does not come during use.

It comes when pressure builds up because of something like a constant short.

Instead of building pressure and disabling itself, it’ll let off the electrolyte everywhere as long as the pressure is there.

Do you only have one 18650 like this, or are all of them like that?

Chatika_vas_Paus · 2019-05-12T19:58:33.000Z

Unfortunately, the whole package. The plate was apparently very good welded.
I have already broken the plate from many batteries, but now first time I’ve made the holes.

Barkuti · 2019-05-12T21:58:56.000Z

In order to remove nickel strips from strongly welded cells it is advisable to do it gently, wiggling carefully. Or even use an electrical cutter first, then use a grinding stone to remove remnants and smooth out the surface, carefully and minimizing abrasion. Too much abrasion will cause surface oxidation, which is pretty bad for contact resistance.

Cheers :-)

FlashKat · 2019-05-12T22:10:52.000Z

I would dispose of those batteries, and just buy good name brand batteries.
The money you save is not worth your safety/life.

Macka17 · 2019-05-13T00:45:01.000Z

Silly Question. NO.NO.NO.
Get as far away as possible from them.
Gassing in any acid pack is a potential explosion.

Samsung. LG, and Dell Are the only cell packs I use.
Usually LG or Samsung cells in there. and they usually made up of the good old Panasonic internals.

I’ve been lucky so far.
Any I can’t just twist/wriggle, and pull.
Goes in bin for dump run.
They NOT worth risking your body parts for.
I always take out all my battery’s every 3 months or so too.
ALL of them. and run through the chargers.
Keep them at 4.2.
Very few of them drop any volume. Apart from the used ones.

I read somewhere it is good to store them at around half?
discharge capacity.
Why not full….

For others here as well as myself. Probably not too many actually KNOW. (I’d like to)

BlueSwordM · 2019-05-13T01:28:39.000Z

Well, keeping them at 3,4V-3,7V allows them to stay at full health as long as possible, and self discharge as minimally as possible.
The lower the storing voltage, the better for the health.
At 3,4-3,5V, they might as well be sold as new no matter how much time passed.

The reason being that the close you are to the full charging voltage, the more chemical reactions can take place, and the total self-discharge rate of the cell is higher as the cell gets close to the 4,2V.

That’s due to oxidation potentials being lower, but there are other advantages:

If you have a fire, a 3,4-3,5V cell is much safer than a fully charged 4,2V cell. This is why all the cells that have been salvaged and tested are discharge down to 3,5V.
They actually lose less charge if they are charged at a lower voltage.

After 3-5 years, a once fully charged cell might have gone down from 4,2V to 3,3V, and perhaps even lower.
A partially charged cell(3,4-3,5V) will stay at that voltage for even longer. I have the experience of cells still being at 3,5V even after so long.

Macka17 · 2019-05-13T07:26:05.000Z

Thank you.
I. And probably others didn’t know that.
I won’t boost mine to full anymore.
I’ll change them round in torches and take them down to the 3.4/3.5. ok.

Just keep the current battery’s in actual torch use at max.

You live and learn.

MontyPyfon · 2019-05-13T09:15:42.000Z

I am confused. Surely if I charge a cell to 4.19V and then store it, after some time it may drop to 3.5V. Would it then not stop at this level and last for several years? Just like if I had charged it to 3.5V and then stored it. Inquiring minds would like to know.

MontyP

BlueSwordM · 2019-05-13T13:03:22.000Z

Well, when going down from 4,19V down to that 3,5V, the cell incurs internal damage, and has a higher overall self-discharge due to the past oxidation reactions inside of the cell.
Doesn’t happen as much at lower voltages.

What matters is the time spent at that voltage.

It doesn’t matter if it stays and is used periodically in a flashlight. being discharged down to around 3,9V-4,0V.
At that point, it doesn’t matter too much.
It matters if you charge your cells at 4,2V then store them.
It matters much much more if you keep your cells constantly at 4,2V.

TLDR: Store at 3,4-3,5V for very long periods of time.
Store at 3,9-4,0V for most periodical usage.
Charge to 4,2V if you use the torch a lot.