Fire Extinguishers

[Mrjmegson]

Hey guys,

The wife is a bit of a stress head (aren't they all), and has made me fit a smoke alarm in the under stairs where all the solar kit is.

But she also wants a fire extinguisher.

So, which one should I get?

I've read that electrical fires need either CO2 or powder, but then have come across extinguishers specifically made for Lithium battery fires, which weirdly have water in them as one part. I'm assuming they will also work on electrical fires, just in case the inverters went up.

What are your thoughts?

Jay

 

[roys]

Powder not recommended for indoor use.
CO2 all the way for me.

 

[Richard-the-Ninth]

In general electrical fires should be extinguished with either CO2, dry powder or watermist, but drypowder is not good in confined spaces as it soon reduces visibility.
Lithium batteries have a problem, that once the fire has been extinguished the battery can still reheat and reignite, that is where the lithium fire extinguisher comes in, not only will it extinguish a fire it also coats everything with a thin layer of vermiculite which stops re ignition.
You can get small lithium extinguishers from Amazon but in an ideal world you should get on big enough for the capacity of the batteries you have.

 

[Mrjmegson]

Cheers Roy, I hadn't read that about powder.

Have you seen the Lithium battery extinguisher?

 

[Mrjmegson]

Hi Richard,

Thanks for that very detailed reply, that's really appreciated.

I have 40kwh of batteries, so how would I work out how big an extinguisher I need?

And are the lithium extinguishers ok to use on a general electrical fire, so for the inverters?

Cheers.

 

[Mrjmegson]

I've just looked at some of the lith ex ones, and the biggest one is rated for 250 to 500 wh, so they wouldn't be anywhere near able to tackle a fire in my batteries, or am I reading that wrong?

 

[Richard-the-Ninth]

As with any fire extinguisher, it would depend on how big the fire is, and how quick you are. The earlier you tackle it the smaller the fire should be.
On a personal note, I prefer to have several small fire extinguishers than to have one large one, although the large one will work, if you only use 50% of it, you can not keep the other 50% as once used any fire extinguisher will leak over time.
As for using a lithium fire extinguisher on an inverter, you can, it will work, but I would use CO2 as you can get a 2kg size for only £34
I have a 2kg CO2 sitting to my left, as I type.

 

[SPECIAL LOCATION]

I've just looked at some of the lith ex ones, and the biggest one is rated for 250 to 500 wh, so they wouldn't be anywhere near able to tackle a fire in my batteries, or am I reading that wrong?

Daft question maybe...

but have you tried asking your local fire brigade for advice?

They may be able to point you in the right direction about what's most suitable..

 

[Mrjmegson]

Not a daft question at all, and the answer is no, my first port of call was this forum, but now I've realised the complexities of it, thanks to you, I've contacted a supplier to see what they say about the capacity issue.

That's cool, I'll buy a CO2 extinguisher for now for any possible inverter fires, and try to sort this lithium issue.

Thanks for your advice,

Jay

 

[binky]

I would consider fire lining the cupboard and getting the hell out of the house as a better option personally.

I would also look at the chemical composition of the battery, there's 2 types of lithium, one doesn't self propagate a fire, one does.

 

[johnb2713]

Hey guys,

The wife is a bit of a stress head (aren't they all), and has made me fit a smoke alarm in the under stairs where all the solar kit is.

But she also wants a fire extinguisher.

So, which one should I get?

I've read that electrical fires need either CO2 or powder, but then have come across extinguishers specifically made for Lithium battery fires, which weirdly have water in them as one part. I'm assuming they will also work on electrical fires, just in case the inverters went up.

What are your thoughts?

Jay

In general, lithium iron phosphate batteries do not explode or ignite. LiFePO4 batteries are safer in normal use, but they are not absolute and can be dangerous in some extreme cases. Dont bother with a fire extinguisher, work out an escape route should a fire start to get you and your family safe. Let the professionals deal with a very unlikely fire event. Lithium batteries cannot be extinguished, they provide a fuel source and oxygen to feed the combustion. The best you can do really is a fire blanket and throw it over the batteries to stop peripheral damage.
Get the family out of there and call 999.

 

[kerching]

Another advantage of several small ones is redundancy

One extinguisher, it fails, you have no extinguisher
3 small ones, one fails, you still have two to go at

 

[Fleeting]

I agree with @johnb2713 it is best to get out and not fight a fire unless you are competent in fire fighting. Commercial premises are required by law to have fire fighting equipment however only certain trained staff are permitted to use them the usual rule being activate the fire alarm and get out. Using a fire extinguisher holds its own dangers and a CO2 extinguisher works by removing oxygen something you need to stay conscious.

 

[Mrjmegson]

Hey guys,

As always, thanks for taking your time to reply to me, it's very much appreciated.

As you say John, my batteries are Life-Po4, so much safer.

I had watched something about battery manufacturing, and the guy who worked for the manufacturer made a throw away comment about not being able to put them out once they go, but then moved on quickly.

Binky, the entire area they are in is fire boarded, so should contain a fire, all gaps are filled with fire resistant sealant too.

So the general advice is just to get out.

Hopefully I won't ever need to follow that advice.

Fleeting, the CO2 issue had been a concern of mine, I was wondering how it worked, thinking I'll have to just shove the nozzle through the door and pull the trigger.

 

[michael8554]

I saw a video of a UK fire brigade tackling a burning EV.

They submerged it into portable tank of water and left it for 3 days........

 

[johnb2713]

I had a first hand experience of CO2 in operation, not on batteries but on a Rolling Mill in USA that I was involved with programming.

This was a cold rolling process which kerosine is used as a lubricant in a fine mist. The pressure between the rolls is sufficient to cause combustion but the rolls dissipate the heat. That is until a cobble occurs when the sheet material creases / tears etc. Then you have an instant major fire.

The fire can be seen straight ahead and coming out of the left hand part of the mill. The body is my boss legging it. I stayed behind with the mill operator to initiate the fire suppression.
Thats $50,000 of CO2 being dispensed

You can see being heavier than air it lingers. It was quite a problem for escape, we couldn't leave the pulpit without going through the CO2, we were rescued later with breathing apparatus from the USA Fire Brigade.

 

[Mrjmegson]

Wow, that's spectacular.

 

[Richard-the-Ninth]

There is a video of a similar place on YT, but the quality is not good, so here is a better one




At 0.1 it is the electronic sounder to indicate fire detected, 0:22 it is the CO2 that drives the mechanical siren (to indicate it's going to discharge) the MAIN discharge starts at 0:47

Of course it only looks like this because of the amount of CO2 being released, its not that spectacular with a portable fire extinguisher.

 

[johnb2713]

There is a video of a similar place on YT, but the quality is not good, so here is a better one




At 0.1 it is the electronic sounder to indicate fire detected, 0:22 it is the CO2 that drives the mechanical siren (to indicate it's going to discharge) the MAIN discharge starts at 0:47

Of course it only looks like this because of the amount of CO2 being released, its not that spectacular with a portable fire extinguisher.

I was staggered how long it remained there, there are cellars underneath the mill and it was over 30 hours of ventilation before it was declared safe. There were still odd pockets of it around several days later and you were only aware of it due to a pocket worn monitor, breath the stuff in you felt fine but started to go dizzy. Without the monitors you had no idea until it was too late.

 

[Mrjmegson]

That's scary stuff.