Fire!! Never cover LiFePO4 with wood!!!

Just John

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I'm still putting up the smoke detectors
I already have some connected via z-wave to my burglar alarm. I would recommend it as you do, our garage already had a trash can fire a decade or so ago, but I replaced all of the 25 year old smoke detectors about 2 years ago.
 

Just John

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@Just John Z-wave, hmm; cool tech, looks like it will be around for a while, thank you for mentioning that.
Yes, just as an FYI, the Ring burglar alarm system uses z-wave for the wireless contacts, and integrates quite well with the smoke detectors.


Those are the 3 pack I purchased (one upstairs, one downstairs, and the third in the garage).
 

fhorst

making mistakes so you don't have to...
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I'm still thinking the temperature sensor for the fans. It was discounted quickly. The sensor had a battery lug for mounting. I would think that would be positive It could have been pinched between the wood and the the post. I would guess that post is about 9 to 12V negative potential from the more positive fan lug. Just a small pinch would be enough. You don't need the spark to carry enough heat to melt the battery. It just needs some glowing embers on the wood.

The fans were running. This could have been the perfect fire starter with a 9V battery. Only the owner could know where the wire was, how the fans could have drawn the fire/flame. Maybe there's pictures during the disassembly. We are asking a lot for him to remember where the wires were, how the smoke was billowing up past the wood, His house was on fire. I can't even remember where I put my multimeter 15 minutes ago.


The temperature sensor was/is for the fan controller of the inverter.
And not yet placed inside the inverter.

No placement between wood and cell!
That would be a recipe for troubles.

What many people don't know is that the outside of the cell (under the blue wrap) is negative.

If it was in contact with a positive terminal and bare casing, that would do it.

Or the like me, crushing the wire on the negative terminal, where the tip could have touched a positive terminal.

It shows that we always need to be careful with electricity.
 

fhorst

making mistakes so you don't have to...
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Usually, the very last thing that's been modified has a connection to the fault. An amp meter was added and immediately a short occurred when connecting 12V to meter. Did the short cause wire insulation damage?
The ammeter was in the solar line, nothing to do with the battery.
That did not change for weeks.

Except covering it with the sheet of MDF.

It wasn't just charcoal, it was glowing red, smoldering.

I'm not afraid to use my plywood for the sides.
It is the "water proof" type who is also flame retardant.
Besides, if the sides catch fire...
There are bigger problems then the smoldering plywood :)

My walls of the battery room are made from the same plywood and covered with 4mm concrete fiber sheet.

I should have had a smoke detector there.

For fire, I now have a halotron tank, that will automatically open on 68 Celcius, putting out all fire in 3 meter radius. (No oxigen), leaves no residue and is "safe" for human and environment.
Where the room is 1.20*2, 2.25 high...
Fire doesn't stand a chance.
IMG_20210315_213233.jpg

You hang it on the ceiling.

For fire, there are 3 important steps:
1. Prevention, it should not start.
2. Delay, use flame retardant products so there is time to get equipment to take out the fire.
3. Distinguisher!!! (For electrical fires)

And as most of us aren't always close to their battery, this is a "perfect" solution.
It doesn't eat away the electronics after fire
It doesn't need cleaning.
Relative safe.
(Especially compared to CO2, 2 breaths and you are a dead man)
 

Freep

Solar Addict
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I use 22awg silicon insulated tin cable. It self fuses at 10amps and the insulation doesn’t melt. Perfect for BMS sensing wires.
I did the same thing! It's also much more flexible and easy to organize. I think this should be in a FAQ somewhere.
 

fhorst

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Bud Martin

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Aug 27, 2020
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About $125,-
While yet again a larger investment, I think it's cheap, for what it does and how it protects.
That is not bad, I still have my HALON 1211 2.5lbs that I bought it cheap a long time ago <$100, now it is about $350.
 

Hedges

I See Electromagnetic Fields!
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Mar 28, 2020
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About $125,-
While yet again a larger investment, I think it's cheap, for what it does and how it protects.

Make sure area is enclosed without drain for heavier than air gas, at least deep enough to cover what you want to protect.
Halon or similar will spill to the floor and escape if it can. Hot materials when once again exposed to air can reignite (I've seen it with an oil-covered engine.)

Because power extinguishing agents stick to surfaces, they are better in that regard (where their damaging effects are tolerable.)
 

Hedges

I See Electromagnetic Fields!
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I thought my short was bad.

"20kA, 100A disconnect rated to 200kA"

It is meant to withstand a 200kA fault, hold together long enough for fuse to clear.
My heavy-duty switches are similarly rated. (I have 30A and 200A, 600V AC/DC)

But it isn't meant to interrupt that much current.
 

fhorst

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@Hedges , the tank is supposed to stop all fire in a 3*4 meter room.
Should be at least 2.5 Meter high, as the tank is attached to the ceiling (about 30 cm)
The electricity room is about 1/4 of that area ....

I have to make a check valve for the air inlet.
Something simple as blinds will do just nicely.
images (18).jpeg
Thanks for the tip, as at the moment it's open!
 

unsubscribed

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Nice. I'm constantly amazed by the photos I see here of bare terminals. We don't allow that in aircraft systems.
 
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