Will Li-ion Explode due to shorting?

[ma_sha1]

I recently shorted out two DX C Li-ion & that scared the crap out of me, as I read several post on CPF where people saying Li-ion may explode if shorting out & MY C Li-ion would be a small Granade?

I felt lucky that my C li-ion died immediately after a short & I always measure the Volts before charging so NEVER CHARGE A DEAD BATTERY!
(That may indeed lead to fire & Explosion)

But then I found the TSA site stating that Li-ion will not explode due to shorting. (Link below)
The article also made me feel better stating lithium-ion can be extinguished normally, I Plan to stop using Primary Li, which seems to be more dangerous?

Could some Li-ion experts here clear out the air on this?
Will Li-ion catch fire or explode when shorting out?
Has anyone actually saw a Li-ion caught on fire or explode due to shorting?

http://74.125.45.132/search?q=cache...ing&cd=3&hl=en&ct=clnk&gl=us&client=firefox-a

 

[csshih]

I don't know much about DX's offering.. was it a protected cell? If so.. the protection circuit probably triggered, and stopped the cell from further harm.

 

[greenLED]

But then I found the TSA site stating that Li-ion will not explode due to shorting. (Link below)
The article also made me feel better stating lithium-ion can be extinguished normally, I Plan to stop using Primary Li, which seems to be more dangerous?

Could some Li-ion experts here clear out the air on this?
Will Li-ion catch fire or explode when shorting out?
Has anyone actually saw a Li-ion caught on fire or explode due to shorting?

http://74.125.45.132/search?q=cache...ing&cd=3&hl=en&ct=clnk&gl=us&client=firefox-a

The answer is: it depends.

If the cell is protected, that should prevent most "catastrophic failures".

While we call those "explosions", in reality it's closer to "venting with flames". That is probably what the TSA document is talking about when they say those batts don't "explode". (Technically, that's correct. However that doesn't mean they won't go )

If not protected, the answer is YES, it will, and will do so violently! There're many threads documenting exploding events here on CPF. Some people have even caused them on purpose in an effort to figure out under what circumstances the explosions might occur.

 

[ma_sha1]

I should add that DX only offer C Li-ion in unprotected form.
So these cells I shorted out were Un-Protected & suffered instant death (The batteries, not me :devil:
but no heating up, no fire & no explosion.

Any links to those posts who have shorted out li-ion cells?

 

[greenLED]

Any links to those posts who have shorted out li-ion cells?

Sure, there's a big "Google search" field on the top of every CPF page. :nana:
venting with flames, li-ion safety, li-ion explosion are just some of the many keywords you may try.

There's also links in the "threads of interest" stickies.

 

[ma_sha1]

I've read a lot of CPF links on Li-ion, also searched extensively
with various of terms such as shorting Li-ion, sort out li-ion etc.

There are a lot of links "claiming" shorting of Li-ion will vent to flame or explode, but there's NOT a single case stated where it really happened
due to short out. Most people are just copying each other's opinions, when the first opinion was wrong & it get copied many times, it tends to look like facts but it's not.

I am looking for evidence, not opinions. Anyone one has any real evidence?

Sure, there's a big "Google search" field on the top of every CPF page. :nana:
venting with flames, li-ion safety, li-ion explosion are just some of the many keywords you may try.

There's also links in the "threads of interest" stickies.

 

[SilverFox]

Hello Ma sha1,

Usually, batteries don't explode. They rapidly vent, sometimes accompanied by flame.

The recall of the laptop computer batteries involved the discovery that contamination during manufacturing led to internal shorting of the cells. This shorting led to increased heat, which set the stage for thermal runaway.

I believe a few of those resulted in rapidly venting with flame incidents.

It is possible to protect a cell against internal, and external shorting, but not all cells offer that protection. The main concern is approaching temperatures that initiate and sustain thermal runaway. I believe this occurs at around 300 F, internally.

Here is an article that goes a little more into this.

I believe on CPF we have only had 1 or 2 cases where a cell shorted out and rapidly vented with flame. The one that I recall involved charging a cell that had been over discharged, and ended with some damage to a motel room. You will have to do some searching to find that post, but it should be in the batteries section.

Tom

 

[wapkil]

Hello Ma sha1,

Usually, batteries don't explode. They rapidly vent, sometimes accompanied by flame.

The recall of the laptop computer batteries involved the discovery that contamination during manufacturing led to internal shorting of the cells. This shorting led to increased heat, which set the stage for thermal runaway.

The question is really interesting. All the incidents with recalled batteries that I heard about were caused by an internal shorting. I think that the release of energy during an external shorting would have to be much slower. Would it still be possible to lead to a thermal runaway with it?

 

[ma_sha1]

Tom,

Thanks very much! the link is very helpful. From CFP reading, I've learned that the greatest danger comes from Charging & I always measure the battery volts before charging making sure I am not attempt to charge a faulty battery.

However, my experience with the DX li-ion C cell make me believe that
this DX unprotected CLi-ion may have a internal fuse? that gets cut when there's an external short? Therefore, provide some kind of protection even it's "Unprotected" Li-ion & apprears to be safer than I originally thought?

Just wondering if anyone else have noticed it.

 

[SilverFox]

Hello Wapkil,

I have found that when you test batteries at high discharge rates, they heat up. I have my CBA set to terminate the discharge if the external cell temperature gets too hot. I have had many Li-Ion cells trip the over heat shut off during the discharge.

I have no idea what the internal cell temperature was, but the cells didn't vent or deform, so I am still below thermal runaway. I have no doubt that if I didn't use the thermal shut off things would be different and I would have to conduct my testing inside a bunker...

Tom

 

[SilverFox]

Hello Ma sha1,

Saft cells are manufactured with an internal fuse. I don't know if whoever manufactures the cells for DX does something similar.

Tom

 

[wapkil]

Hello Wapkil,

I have found that when you test batteries at high discharge rates, they heat up. I have my CBA set to terminate the discharge if the external cell temperature gets too hot. I have had many Li-Ion cells trip the over heat shut off during the discharge.

I have no idea what the internal cell temperature was, but the cells didn't vent or deform, so I am still below thermal runaway. I have no doubt that if I didn't use the thermal shut off things would be different and I would have to conduct my testing inside a bunker...

Tom,

Thanks for the answer. You may want to use an ammunition or gunpowder magazine in the bunker. I think they should have a better ability to withstand an internal explosion

To what temperature do you set the discharge safety cutoff?

 

[SilverFox]

Hello Wapkil,

I have it set for 160 F. The temperature probe is calibrated at 140 F. Most of the time the cell external temperature is less than 120 F.

Tom