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Fire Safety with Lithium and Lithium Ion batteries

goninanbl00d

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As you all know, there have been a spate of battery explosions over the past few weeks involving lithium and lithium ion batteries. This isn't anything new (remember the laptop battery fires?), but as lithium batteries become more common amongst the laser community, safety is one of the most overlooked issues with them.

There are two types of lithium batteries- lithium primaries (which contain lithium metal) and lithium ion rechargables (which only contain lithium compounds). Both are extremely dangerous if used incorrectly.

In Lithium primary cells, the lithium metal is expended as the cell is depleted, whereas with lithium ion rechargables the compounds remain, albeit in a lower-energy state.

Lithium ion batteries are rechargable, however, lithium primaries are NOT. Attempting to charge lithium primaries may result in a fire and/or explosion.



Charging and storage


Lithium ion batteries should never be charged unsupervised, regardless of whether they are protected cells or not. Check the cells every hour (at the very leas), and quickly unplug the charger if they are too hot to touch. Move these cells outside in an area away from flammable materials, and allow them to cool. It is inadvisable and dangerous to use overheated cells.

Charge the cells in a metal box, preferably along the lines of a large ammunition box. Do NOT use a completely sealed box, as that will only turn the box into a fragmentation grenade when a battery does explode. The box will also contain any lithium metal in case of a leak or fire.

Before storing batteries, ensure that they are not shorted out by any objects, including other batteries. It is advised to use plastic battery cases to store batteries in.



Extinguishing Lithium Fires


So, you've taken all the correct precautions when charging, but a battery burst. What happens now?

Firstly, remember the days of High School chemistry class? Lithium is an alkali metal- and as a result it's very reactive. Once a lithium fire starts, it's incredibly hard to put out.

The WORST thing you can do is to throw water on it. Lithium will react with the water to produce hydrogen gas, which will only intensify the fire.

The other problem is that most household extinguishing agents don't do terribly much for a lithium fire either. Being a Class D fire (combustible metal), most extinguishing agents will react in an adverse way to it (e.g. water and foam), or will not work at all. (e.g. dry chemical*)


*There is a difference between dry chemical and dry powder. The terms are not interchangeable.

Metal fires will often burn hot enough to be able to strip the oxygen from CO2 and continue burning. They will also break down Halon and related agents into hydrogen chloride into other toxic compounds. Sodium Bicarbonate (Class BC dry chemical) and ammonium monophosphate (class ABC dry chemical) extingushers have little to no effect.

In the heat of a fire the chemicals in lithium ion batteries may also decompose to form lithium metal. This lithium metal combusts more violently than lithium compounds, and also releases dense lithum oxide smoke, which is an irritant.

Extinguishing these fires isn't an easy task. Better not let the fire start in he first place- however, sometimes accidents do happen. Short of investing in a (very expensive) Class D dry powder extinguisher, there's not much common fire extinguishers can do.

When fires do happen, you've got two options- dry sand, or dry table salt. Both work equally well in large amounts. You will need at least two kilos, with 3 or 4 if you have lots of batteries stored together.

Note the emphasis on the word dry. The extinguishing agent must be kept in an enclosed container, free from all moisture before use. Any water, even miniscule amounts, will react with the lithium and intensify the fire. One of the best options is to store it in one of those larger cookie jars with the rubber seal on the lid. Do not expose the extinguishing agent to the atmosphere.

If possible, tape a bag of silica gel dessicant to the lid of the jar. This will help to keep the agent dry.

Store a long-handled metal spade or ladle near the jar. Using your hands, or the jar itself, is a very bad idea. Keep the spade with the jar at all times.

Applying the extinguishing agent is easy- simply scoop the stuff from the jar, and cover the burning lithium fragments with it completely. Do not leave any parts of the burning material exposed to air. Continue to pile the sand or salt over the material until it is covered with at least two centimeters of sand or salt.

If possible, cut power to the charger (if the battery is still in the charger) before extinguishing. If this is not possible, then apply the extinguishant first.

Remember- common sense applies here. In an explosion, flammable material will be sprayed all over the room. Put out the material near flammable materials first (near wood, paper or clothes).

The sand works because it cuts off the oxygen supply to the fire, and quickly draws heat away from the fire. (removing two elements from the fire tetrahedron)

The salt works because it melts, and forms a thin, molten blanket over the material, cutting off oxygen supply to the burning metal. Salt also cools the burning metal, but not as well as sand or copper powder (found in Class D extinguishers).

So, that's it. There's not much needed, but basic safety precautions (jar of sand/ salt, and a spatula) can easily save you from $$$ worth in property damage.

The jar isn't any different from a proper Class D extinguisher (save for the fact you have to scoop it on yourself). They either use salt or copper powder as an extinguishing agent, and it works.

A quick dot-point summary of everything above, by charliebruce. Nice, short points that are easy to remember:


Whilst storing:

* Store in a strong box (ammo case?)
* Avoid short-circuiting them
* Remember that pressure is a problem as well as the shrapnel produced - a completely sealed box is not ideal.


Whilst using:

* Never mix charged and part-charged cells, or disposable and rechargable cells.
* If they get more than mildly warm then stop using them and consider replacing - if they ever get too hot to touch when charging or discharging, then dispose of them.
* Never use any cells you aren't confident are safe, especially in high-current appliances (torches, high powered lasers etc) - you can see the results of torch explosions elsewhere and it isn't pretty.


Whilst charging:

* Make sure they are rechargeable types!
* Never leave them unattended, especially in the first section of charge cycle.
* Charge in a safe container (similar to the one for storage) but keep your "storage" and "charging" boxes separate - if your charging batteries have a problem, you don't want them near the other cells!
* If they get uncomfortably hot (greater than body temp.) at any point, especially in the first hour of charging, then stop charging them for a while. If they get very hot indeed, stop charging them and when cool, dispose of (recycle) safely.
* Always have an appropriate extinguisher nearby (DRY Salt or sand).


In the event of fire:

* Cut power to the charger/device first.
* Never use water or CO2 - only DRY sand or salt.


 
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charliebruce

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Very good information indeed there - that's pretty comprehensive. My main suggestion is that the people who aren't going to read through it fully, are the ones who need the information most. I'm not sure if a summary of what needs to be done would be a better option for those people? I put together some bullet points, feel free to use in the guide if you think it's useful.


Whilst storing:
  • Store in a strong box (ammo case?)
  • Avoid short-circuiting them
  • Remember that pressure is a problem as well as the shrapnel produced - a completely sealed box is not ideal.

Whilst using:
  • Never mix charged and part-charged cells, or disposable and rechargable cells.
  • If they get more than mildly warm then stop using them and consider replacing - if they ever get too hot to touch when charging or discharging, then dispose of them.
  • Never use any cells you aren't confident are safe, especially in high-current appliances (torches, high powered lasers etc) - you can see the results of torch explosions elsewhere and it isn't pretty.

Whilst charging:
  • Make sure they are rechargeable types!
  • Never leave them unattended, especially in the first section of charge cycle.
  • Charge in a safe container (similar to the one for storage) but keep your "storage" and "charging" boxes separate - if your charging batteries have a problem, you don't want them near the other cells!
  • If they get uncomfortably hot (greater than body temp.) at any point, especially in the first hour of charging, then stop charging them for a while. If they get very hot indeed, stop charging them and when cool, dispose of (recycle) safely.
  • Always have an appropriate extinguisher nearby (DRY Salt or sand).

In the event of fire:
  • Cut power to the charger/device first.
  • Never use water or CO2 - only DRY sand or salt.
 
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goninanbl00d

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Thanks for the tip.

Mind if I add it into the first post (with reference to you, of course)?
 

pseudolobster

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To dispose of lithium cells, you should first discharge them. If your battery gets too hot to touch at any point, you should throw it out, but before you do, you should get them down to 0 volts so they can't explode in your garbage can or at the dump. I'm told the best way to discharge lithium cells for disposal is to put them in salt water overnight. Salt water conducts electricity, albeit weakly. You'll want a lot of salt, at least 5-10%. When you've left them overnight, pull them out and test them with a multimeter. If they have more than half a volt of juice in them, put them back in the salt water till they're completely dead. From everything I've read, once they're neutralized, they're completely safe to dispose in your regular trash. I'm not really an expert, but from what I've been told, the lithium will be incapable of a reaction, and disposing them in your regular garbage should be completely safe and legal.
 

goninanbl00d

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To dispose of lithium cells, you should first discharge them. If your battery gets too hot to touch at any point, you should throw it out, but before you do, you should get them down to 0 volts so they can't explode in your garbage can or at the dump. I'm told the best way to discharge lithium cells for disposal is to put them in salt water overnight. Salt water conducts electricity, albeit weakly. You'll want a lot of salt, at least 5-10%. When you've left them overnight, pull them out and test them with a multimeter. If they have more than half a volt of juice in them, put them back in the salt water till they're completely dead. From everything I've read, once they're neutralized, they're completely safe to dispose in your regular trash. I'm not really an expert, but from what I've been told, the lithium will be incapable of a reaction, and disposing them in your regular garbage should be completely safe and legal.
The lithium compounds can still react, albeit with much less energy than a fully charged cell. Most countries require you to take the battery to a disposal centre, and so does the EU.

If a cell overheats during charging, it's probably defective and shouldn't be used.
 

Kevlar

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Very informative thread, thank you for compiling all that info here for us.

It wouldn't hurt to make this a sticky :)
 

00Giorge

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To dispose of lithium cells, you should first discharge them. If your battery gets too hot to touch at any point, you should throw it out, but before you do, you should get them down to 0 volts so they can't explode in your garbage can or at the dump. I'm told the best way to discharge lithium cells for disposal is to put them in salt water overnight. Salt water conducts electricity, albeit weakly. You'll want a lot of salt, at least 5-10%. When you've left them overnight, pull them out and test them with a multimeter. If they have more than half a volt of juice in them, put them back in the salt water till they're completely dead. From everything I've read, once they're neutralized, they're completely safe to dispose in your regular trash. I'm not really an expert, but from what I've been told, the lithium will be incapable of a reaction, and disposing them in your regular garbage should be completely safe and legal.
That might be in Canada but where I am you are not supposed to put lithium batteries in the garbage. You take thm some where like Best Buy and they have a drop. I was also told never completely discharge a lithim battery, they can explode, maybe in the water thing might work and for storage manufacturers recomend a 40 percent charge. I use a lipo charge bag for all of my batteries they are cheap at $5.75 lipo bag.gif

I have Liion and Lipo batteries the Lipos are 22.2v and 3000mah after seeing videos they spook me and when not in use they remain in the bags and at 40 percent charge. Read this link http://www.batteryuniversity.com/partone-5B.htm
 
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millirad

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Good lithium safety information! Yes, I remember seeing the small piece of lithium metal race around on the top of some water in Chem class years ago............

 
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goninanbl00d

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Good lithium safety information! Yes, I remember seeing the small piece of lithium metal race around on the top of some water in Chem class years ago............

That, ladies and gentlemen, is why you don't use water when extinguishing lithium fires.

That is also why a dry extinguishing agent is VERY important.
 

pseudolobster

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The lithium compounds can still react, albeit with much less energy than a fully charged cell. Most countries require you to take the battery to a disposal centre, and so does the EU.
That might be in Canada but where I am you are not supposed to put lithium batteries in the garbage.
I read a few things that said once you discharge a lithium cell to 0 volts, all of the lithium becomes locked up in salts, which pose no more damage to the environment than the rocks they were originally mined from.

I may be completely wrong though, passing on bad second-hand information... If anyone with some academic experience on the matter could chime in, I'd appreciate it..
 

goninanbl00d

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In lithium primaries, the lithium metal is gone after it is fully discharged.

In lithium ion rechargables, the lithium is still in a compound form, albeit in a less reactive one. Nonetheless, discharged LiIons are still flammable.
 

Jimmymcjimthejim

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Excellent thread.
I have a question about the salt water though. Wouldn't it be dangerous to put a lithium battery into water? I'm no professional, but it seems like a bad idea to me.
 

Markus Unread

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Another Lithium Ion battery tidbit. After seeing many laptop batteries die prematurely, I ran across an article explaining what effects change their overall lifespan.
Basically, the higher the charge+the higher the temperature=the shorter the life span. Excluding "dead flat", which is fatal.
Suddenly, it made sense why topped-off batteries sitting in hot laptops died earlier deaths than ones that were idle with less charge.
If I am not using a Lion for long periods of time, it goes in a ziplock and into the fridge.
Seems to be working. When I pull them back out, they haven't self-discharged nearly as much as they did at room temperature.
 

mewrox99

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Haha I depose of my lithium primaries in an environmentally friendly, responsible and intelligent way.

I heat them strongly with a blow torch resulting in a them making a loud bang and flames :cool:

Yeah I'm a retard
 

Markus Unread

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Haha I depose of my lithium primaries in an environmentally friendly, responsible and intelligent way.

I heat them strongly with a blow torch resulting in a them making a loud bang and flames :cool:

Yeah I'm a retard
Just don't add "get really drunk and..." to the front of that. I'm surprised that you use a torch instead of plugging them onto the AC power :eg:
 




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