Happened again, DIY battery fire

OffGridForGood said:

From some of the common stats online, it would seem to limit house fires we should ban Natural Gas, Smoking and Kitchens !!

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Ban that shitty assed flexible gas pipe and go back to black iron pipe might be a good start.

I'd love to see some research showing the effectiveness of these small aerosol devices designed to be mounted within the battery. I bet they are very effective in achieving their design goal of getting various types of safety certifications passed for the pack.

Imagine a cell vents due to some internal manufacturing issue. It emits combustible vapour. Every single "big blue" cell I saw a datasheet of is in the tested for "no fire" on puncture/venting on its own. It needs an ignition source for the flammable fapour emitted to catch fire.

Most lithium cells have electrolytes based on ethylene carbonate or dimethyl carbonate. Both ignite in air at temperatures in excess of 400C (800F). So we need something that hot (or a spark) to cause fire. A melt fuse could be such a thing. We've learnt that and most recent builds on this site I see use T-class or NH type fuses which are enclosed in a ceramic container. So they shouldn't ignite anything.

One of the challenges not addressed in current battery pack designs is adjacent cell heating during another cell failure. Imagine we have cells sitting compressed one next to the other with fire resistant insulation i between (fr4 or textolite). When that one cell reaches 250C what happens to the others surrounding it? Anecdotal evidence from single cell venting events seems to suggest they're fine, but I'm not so sure.

Providing sufficient compression and thermal isolation between cells at the same time seems to be the next "safety innovation" in diy packs.

I wonder if there is some heat insulation we could use between cells that could survive the temperature and the pressure. Of course this would increase the cooling requirements of the pack. Any ideas what to use?

JRH said:

WD- 40 drops em like a rock…spiders ,ants ,bees and probably other stuff too …amazing results.
( #7 birdshot works pretty good too…)

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Lots of bug solvents available.

Luk88 said:

I'd love to see some research showing the effectiveness of these small aerosol devices designed to be mounted within the battery. I bet they are very effective in achieving their design goal of getting various types of safety certifications passed for the pack.

Imagine a cell vents due to some internal manufacturing issue. It emits combustible vapour. Every single "big blue" cell I saw a datasheet of is in the tested for "no fire" on puncture/venting on its own. It needs an ignition source for the flammable fapour emitted to catch fire.

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What is the trigger that will initiate the aerosol device?
If it is heat, venting caused by over-voltage doesn't trigger it, unless ignition occurs?

There are no fire prevention devices that can be placed near a battery system that will keep solar panels from catching fire. (What this story actually was about)

wpns said:

Lots of bug solvents available.

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Yep. I get concentrated Bifen XTS for my yard at a local farm supply store. I mix it at 2x the recommended levels and don't get bees, ants - nothin. I use the Bifen IT for inside and haven't seen a bug of any kind inside the house since I built it 2 years ago. Once a year application for both.

I bought one of these fire suppression modules to put into my DIY battery box: https://a.aliexpress.com/_mKr0cX0.



For now I just have it attached to the top of the inner wooden box, but I may mount it underneath the lid to be closer to the cells. I need to check if there's enough clearance for it. It's supposed to activate at 170C. Will it actually work in an emergency? I don't know, but I feel like it's better than nothing.

timselectric said:

There are no fire prevention devices that can be placed near a battery system that will keep solar panels from catching fire. (What this story actually was about)

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I actually laughed, thanks.

Yes, that is very true.

offgrid-curious said:

I bought one of these fire suppression modules to put into my DIY battery box: https://a.aliexpress.com/_mKr0cX0.

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For now I just have it attached to the top of the inner wooden box, but I may mount it underneath the lid to be closer to the cells. I need to check if there's enough clearance for it. It's supposed to activate at 170C. Will it actually work in an emergency? I don't know, but I feel like it's better than nothing.

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I wanted to research how these aerosol type "hot gas" extinguishers work, but Internet archive is down and Google is useless...

OffGridForGood said:

What is the trigger that will initiate the aerosol device?
If it is heat, venting caused by over-voltage doesn't trigger it, unless ignition occurs?

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I believe it triggers on high temp signal from BMS (over 150F or something). At least the ones inside eg4 batts.

Luk88 said:

I wanted to research how these aerosol type "hot gas" extinguishers work, but Internet archive is down and Google is useless...

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This would be a great post for the Danger Zone! forum!

offgrid-curious said:

I bought one of these fire suppression modules to put into my DIY battery box: https://a.aliexpress.com/_mKr0cX0.

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I though you were talking about the box. What kind of container is that? Is like thick fiber walls with a metal frame on it?

Luk88 said:

I wanted to research how these aerosol type "hot gas" extinguishers work, but Internet archive is down and Google is useless...

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In the description of the product there is a small explanation. I think it means that the device emits a two component aerosol that reacts endothermically cooling everything enough to stop or reduce the fire. Idk if that would work in a Lifepo4 fire though.
I am done with google too. I am trying yandex, duckduckgo or even bing.

hwy17 said:

It might seem that way. But I assure you it is my earnest opinion.

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Oh, IT IS THAT WAY, I assure you. This is a DIY solar forum, not a disgusting dirty coal forum, but do what you must to feel relevant, by all means!

John Kelly said:

Oh, IT IS THAT WAY, I assure you. This is a DIY solar forum, not a disgusting dirty coal forum, but do what you must to feel relevant, by all means!

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Coal powers prosperity and saves precious natural gas in the ground for the benefit of future generations. The poor EROI and intermittency of solar will prevent it from entirely replacing fossil fuels.

I am here on this forum because I know that we are allowed to have our different opinions here, unlike the reddit echo chamber where discourse is banned.

hwy17 said:

Coal powers prosperity and saves precious natural gas in the ground for the benefit of future generations. The poor EROI and intermittency of solar will prevent it from entirely replacing fossil fuels.

I am here on this forum because I know that we are allowed to have our different opinions here, unlike the reddit echo chamber where discourse is banned.

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Is not that you are not allowed but you sound kind of coo-coo or just trolling. Solar return of investment is good, and you step up your life's quality a lot when you produce a lot of energy for yourself. Why on earth would you be against that?

Aridom82 said:

Is not that you are not allowed but you sound kind of coo-coo or just trolling. Solar return of investment is good, and you step up your life's quality a lot when you produce a lot of energy for yourself. Why on earth would you be against that?

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I think my genuine participation here verifies that I am not a troll. Kookoo, maybe.

Public policy has set the parameters of the game, and I am forced to play it so I will.

If solar's promises had paid off and it had brought plentiful affordable energy to California I can tell you I wouldn't be here, I'd be off pursuing other hobbies and just paying my bill. But luckily this one makes a good hobby too.

Aridom82 said:

What kind of container is that? Is like thick fiber walls with a metal frame on it?

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It is a custom-built metal enclosure made out of 12 gauge stainless steel, with 3" of rockwool insulation on all sides. It's a beast. I'm planning on doing a write-up on it, I just haven't done it yet. There are a couple of details here: https://diysolarforum.com/threads/off-grid-system-upgrade.71025/post-1063501.

John Kelly said:

Oh, IT IS THAT WAY, I assure you. This is a DIY solar forum, not a disgusting dirty coal forum, but do what you must to feel relevant, by all means!

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Quite a few threads about solar, EVs and heat pump technology on a dirty coal forum I frequent during the heating season, since I heat with disgusting dirty coal; powered by my whole house solar system.

OffGridForGood said:

If it is heat, venting caused by over-voltage doesn't trigger it, unless ignition occurs?

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excellent point.

According to the description on the product site of the company manufacturing this aerosol fire extinguisher, it seems to be capable of extinguishing battery fires. The mechanism of extinguishing is also explained. (However, I do not have a background in chemistry, so I do not fully understand how it works.)

Additionally, I found what seems to be the company's YouTube channel. Several videos demonstrating the product have been posted there.

Aridom82 said:

Is not that you are not allowed but you sound kind of coo-coo or just trolling

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I find it hard to believe you are calling Hy17 coo coo for saying that coal is the best, cheapest, and cleanest way. I agree.
The GDP of the USA agrees as well.

PotusGobbleBottom said:

I find it hard to believe you are calling Hy17 coo coo for saying that coal is the best, cheapest, and cleanest way. I agree.
The GDP of the USA agrees as well.

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I am not so you dont have to believe it. The coo coo point is being anti-solar, or calling solar roi poor.
Coal sure is cheap, clean or the best that is arguable.

John Kelly said:

Oh, IT IS THAT WAY, I assure you. This is a DIY solar forum, not a disgusting dirty coal forum, but do what you must to feel relevant, by all means!

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To be fair. What @hwy17 said has a point. 90% of this solar stuff comes from China. Their manufacturing process has made them the most polluting country on our planet. Then when it gets here, most of this stuff cant be recycled economically.
Dont loose the big picture, this is just a different viewpoint.

hwy17 said:

If solar's promises had paid off and it had brought plentiful affordable energy to California I can tell you I wouldn't be here, I'd be off pursuing other hobbies and just paying my bill. But luckily this one makes a good hobby too.

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You couldnt even build a train *railway* in California so i believe that the problem is not in solar but somewhere else.
Solar energy implementation does not have to be a promise or something intangible, is just a clean cut calculation. Nothing political about it.

I take an all of the above approach to energy. Some forms are better suited in different areas/climates/seasons. Solar here is great in summer. It absolutely SUCKS in winter, so you have to have something else during that time, no way around it.

You don't have to be anti solar to be pro coal, and don't have to be anti gas to be pro solar. We don't need false dichotomies around here.