Lithium Polymer Batteries

[Tom Sutton]

I received the following enquiry the other day any views,

I am looking for advice in regards to how to safely deal with a Lithium Polymer fire.
I work for a Film Production company and we use a Lithium Polymer Batteries with our DJI Phantom.
I was wondering if you could give me any advice for dealing Lithium Polymer fires? Such as the best fire extinguisher to use. I am aware that for the most part Lithium Polymer fires are difficult to extinguish and often the best practice would be to notify the correct authorities and controller any secondary fires.

[AnthonyB]

Check the MSDS for the batteries - whilst some liberate free lithium and require a Class D agent, others do not and can be tackled with ABC Powder or Water Mist

A new solution is also Aqueous Vermiculite Dispersion (AVD) fire extinguishing agent:

http://www.avdfire.com/

[nim]

I have had an enquiry from a customer who has had a lithium battery fire where they have expensive electrical equipment powered by Lithium batteries. L2 Powder may be  an option but only if the customer is prepared to accept the collateral damage to other equipment. I have read this article and found out the AVD is only sold as an aerosol which may or may not be sufficient.

I have also found out about F500 but know nothing yet as I am waiting for product literature from the suppliers.

Looking at suppression systems as well.

Does anyone have experience of Lithium Battery fires, F500, AVD or suppression systems for lithium fires and ways of extinguishing/controlling them?

[AnthonyB]

Depends on the type of cell. I had to do an extensive research project into prevention and emergency fire response requirements for a company who specialises in making automotive batteries from lithium ion cells as they had concerns about fire risks from runaways or exposure to other fires.

It was found that as no actual lithium metal was in the cells nor would be generated during normal use, overcharge, runaway or fire that either Water Mist or ABC Powder extinguishers were suitable (Water mist having the advantage of cooling the cells preventing further runaway) with inert gases such as Argonite for the bulk cell store.

Where there is a real risk of there being lithium then one of the various Class D agents would be indicated.

[nim]

Thank for the reply. I have asked the customer  for the MSDS sheet as someone else has already suggested there may not be any lithium in the battery as it may be  made up of various other metals. I've looked at the AVD aerosol extinguisher you have suggested and at the F500 extinguisher option as well.

How well do L2 Extinguishers work. I have been told they must not be disturbed for many hours after extinction because of re ignition.

Someone else has suggested a bucket of sand. Is sand an option?

[AnthonyB]

Dry sand was one of the agents used before the development of specialty powders in the mid 20th Century and is still suitable for small incidents. Also for minor outbreaks bulk Class D powder in pails and applied with scoops is used as cheaper than a pressurised extinguisher.

Standard Class D powders such as Sodium Chloride, Graphite, Copper and Ternary Eutectic Chloride have a high latent heat of fusion and absorb the tremendous heat from the metal to melt and flow over the metal, cutting off the oxygen and smothering the fire. The molten powder solidifies and crusts and can crack exposing the still hot metal to the air with reflash and so large quantities of extinguishing powder are needed to fully cover the powder until it has itself cooled and re-solidified - which can take a long time.

TEC,whilst still manufactured in the developing world, is no longer used here due to cost and extreme toxicity, but did have the added property of chemical inhibition of combustion via it's chloride radicals.

Whilst not appropriate to Lithium it's of note that for Magnesium risks an economy option is the use of ABC Powder extinguishers fitted with low velocity applicators rather than the dearer specialty powders as years ago Croda Kerr submitted ABC 40 to the standard German DIN tests for Class D agents and a 12kg extinguisher was found to extinguish up to 1kg of magnesium.