Cell caught fire !!!

So Rohan has just uploaded a new video of a cell that caught fire...


It's bad that it happened in the way it did ( builder error ) but out of bad comes good and we can all learn from it.

A dead short is all it took. 400+ amps dumped straight into one cell much like in this video with welder hooked up to a cell..

have made a bigger mess, here is what happens when an entire battery pack catches fire.

Wow, it's a good thing nothing major was damaged. Just a reminder of how important safety is with our designs.

It was a crazy 20 min from when I found out and thought to myself DAMAGE CONTROL time from the "burn your house down" crew to when I send the photos to my Sparkie and he saw the issue instantly. I was like must be internal short, or cell was bad in some other way. Didn't think for a minute that it was builder error.

Ive had so many people tell me the future of my modules is this.
Ill be sure to document it if I ever get an 'Epic Fizz' going.

Fire sells better than ice on the old YouTube

OK, I've seen enough of these that I understand why Tesla powerwalls are installed on the EXTERIOR of a house. I'll be hanging mine on an exterior cinder block wall, in some salvaged Steelcase cubicle over-desk lockers, obtained from a local university surplus department.

looks like a very tidy idea, looking forward to seeing it in place.

Still not as good as a disposable shed like you and i have Pete .... <grins>

As soon as I'm cash positive again I'm ripping it all out digging a 40m long 600mm deep trench and starting again

hbpowerwall said:

As soon as I'm cash positive again I'm ripping it all out digging a 40m long 600mm deep trench and starting again

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Burying your batteries? I had thought about that, but decided a sheet steel enclosure was probably good enough.

No, thinking of making a custom shed or maybe a 10f shipping container and turning it into a power room .

hbpowerwall said:

No, thinking of making a custom shed or maybe a 10f shipping container and turning it into a power room .

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Really like this idea. i hope to see it happen one day!

Lux_Gamer said:

hbpowerwall said:

No, thinking of making a custom shed or maybe a 10f shipping container and turning it into a power room .

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Really like this idea. i hope to see it happen one day!

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I'd like to see it happen also, heck of a lot of effort but result sure will be good. Time will tell, i got lots of plans in my head - it's making them appear in real life is the issue. .lol

hbpowerwall said:

Lux_Gamer said:

hbpowerwall said:

No, thinking of making a custom shed or maybe a 10f shipping container and turning it into a power room .

Click to expand...

Really like this idea. i hope to see it happen one day!

Click to expand...

I'd like to see it happen also, heck of a lot of effort but result sure will be good. Time will tell, i got lots of plans in my head - it's making them appear in real life is the issue. .lol

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Yes that is also a big problem for me.

whoa, thats why the bigest thing we need to do is make sure our designs are stored i nthe safety of outside!

I know what you mean Pete, ive been making good progress on my design but work comes first... these skills need to pay the bills before I get fun time

Yeah, safety is key.

After watching most of the videos, I see that Pete's sheds have everything in them and feed AC into the home - yes,the sheds are separated from the home, but there are connection to PV array, the batteries, the inverter/charge controllers, etc. All of this is outside his home, in metal structures and it makes things safer that way. Yet from what I can tell, all of this is still fairly close to the living area (In one of the earlier videos, Pete said that his bedroom is just behind the wall where the shed is). Is more distance better?

With distance comes resistance and drop of power in AC lines. I think it is like a 10% drop per 100 meters or something like that depending on the gauge of the wire and number of amps.

Here is my situation:
I have a very large piece of property - many acres.
A good portion of my PV array set is set up in a very sunny area clear of trees - they are all on the ground on adjustable rails with the ability to quickly change the panel's angles to maximize the sun's rays for different times of the year. That area also doubles as a raised garden, so the panels also provides a little shade for the veggies,
That is another project...a different thread,

BUT, with respect to safety, distance, and voltage/amperage drop due to resistance, I have a few questions and would love your thoughts.
Lets say you have a big shed in your yard - perhaps 100 meters away from your dwelling.
And the PV array another 200 meters away (as is the case in my homestead).

I have conduit buried from the pv array to the shed (it is 24 inches / roughly 600 mm deep) -
I have two similar conduit buried from the shed to my dwelling (one for power, one for fiber and Ethernet connectivity).

I want to bring only the high voltage DC from the shed to the house and then invert it there. At the same place where the grid enters the house.
What implications are there for DC to traverse from the shed to the house?
Yes, high DC voltage (48v) .... distance shouldn't be the same kind of resistance drop as AC.

For safety reasons, why not put everything DC outside, (as above) and run the inverter and so on in the house?

Does anyone have any formulas or thoughts about this?

Thanks!!

I want to bring only the high voltage DC from the shed to the house and then invert it there. At the same place where the grid enters the house.
What implications are there for DC to traverse from the shed to the house?
Yes, high DC voltage (48v) .... distance shouldn't be the same kind of resistance drop as AC.

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Well, you are right. The voltage drop between AC and DC is different. However, your voltage drop assumptions aren't correct. The voltage drop between AC and DC is basically the same (single phase, anyways).
So, if you are going to maintain AC devices in the house, it would be far better to invert it in the shed and feed it into the house. You'll loose far less voltage that way. And, you loose voltage, not amperage.

Using a voltage calculator:
Wire Size 1/0 Copper Wire
Voltage 120V
Single Conductor (1 Wire each way)
Distance from Source: 100m
Load current: 100A
Voltage drop: 6.45
Voltage drop percentage: 5.38%
Voltage at the end: 113.55

Wire Size 1/0 Copper Wire
Voltage 50V
Single Conductor (1 Wire each way)
Distance from Source: 100m
Load current: 100A
Voltage drop: 6.45
Voltage drop percentage: 12.90%
Voltage at the end: 43.55

So there'd be a larger voltage drop, 5.38% vs 12.90%. If you went to 240V, it'd be even better:
Voltage drop: 6.45
Voltage drop percentage: 2.69%
Voltage at the end: 233.55

Now, you could raise your DC voltage to 120V or 240V to send to the house, but now you are getting into safety issues. I would must rather be hit with 120VAC than 120VDC. DC will create a nasty arc that will burn, best case, or lock you muscles up on the wires and cause you to fry in worse case. AC will at least let you have somewhat of control of pulling yourself off.