Battery fire safety

Boron said:

WOW I am so glad the OP raised this topic. It seems that a lot of DIY constructors are unaware of the consequences of a LiB going ape.
Ive just seen an astonishing vid

made from a conference of Fire safety professionals and presented by a a leading expert Professor of 20 + years studying the risks of Lithium battery cells to the public. I though I was being super careful and have realised I need to go one level further and move all such cells out of my house to an outdoor open space as the consequences of getting it wrong are disastrous and battery fires cant be extinguished. I will not be meddling with LiBs indoors anymore - strictly outdoors testing. If one cell goes goes critical it can burn your house down.

Watch this video and make up you own minds - I feel totally chastened and humbled by my own lack of appreciation of what can happen

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Johneb said:

Like a class b foam in a bag over the batteries that would rupture when exposed to flame?

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• a cement board cabinet with a metal frame vented at the bottom. Figure 6" of clearance around the the pack. Sheath in cement board inside and outside of the frame for two burn through layers.
• An oven vent/hood above with a chimney pipe out above the battery pack. If equipped, the fan thermostat could be set to kick on at 10% above maximum rated operating temperature to help cool packs getting warm or vent the presumably hot gasses leaking out of the packs.
• The exterior of the chimney has some type of spark arrester screen like most modern chimney's
• In the event of an "event", the heat flow (or worse flame) goes up the chimney and is exhausted outside of the structure. Even if the fire damages the fan, the air current should keep most of the heat and gasses going up and out of the chimney.

SparkyGage said:

An idea for your consideration:

• a cement board cabinet with a metal frame vented at the bottom. Figure 6" of clearance around the the pack. Sheath in cement board inside and outside of the frame for two burn through layers.
• An oven vent/hood above with a chimney pipe out above the battery pack. If equipped, the fan thermostat could be set to kick on at 10% above maximum rated operating temperature to help cool packs getting warm or vent the presumably hot gasses leaking out of the packs.
• The exterior of the chimney has some type of spark arrester screen like most modern chimney's
• In the event of an "event", the heat flow (or worse flame) goes up the chimney and is exhausted outside of the structure. Even if the fire damages the fan, the air current should keep most of the heat and gasses going up and out of the chimney.

This simple arrangement would not cost much relative to fire damage and would go a long way to "contain" an unfortunate event.

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OffGridForGood said:

And a 20kW heater to keep the vented space warm during 6-months of winter, so the ESS stays warm enough to operate.

yeah, I know, not everyone lives in a cold place.

The fire rated enclosure seems like a good start, but rather than vents and chimney outlet, I think we are better off to seal it tight to contain the 'event' and add smoke and heat detectors to warn us of problems, hopefully before the situation gets out of hand.
I have smoke and heat detectors next to my ESS that alarm in my house (next door) but what I have been thinking of adding is an automatic disconnect tied to the two detectors - to cut off the ESS circuits to interrupt the flow of electricity at the first sign ot smoke or heat.

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SparkyGage said:

I've never seen a one size fits all solution for anything (that really works). Not living in that environment, I couldn't comment. I'm in an environment that will be concerned with batteries staying below their maximum operating temps. My building where my system is headed stays above freezing if the outside is above 0F.

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