Comment by shakna
6 months ago
If you want more of the story, probably start over here [0]
[0] https://secondlifestorage.com/index.php?threads/glubuxs-powe...
6 months ago
If you want more of the story, probably start over here [0]
[0] https://secondlifestorage.com/index.php?threads/glubuxs-powe...
Jesus. No cell balancing, protection or monitoring that I can see, and most importantly - wires directly soldered onto the battery instead of spot-welded. That's a fire hazard waiting to happen.
People, if y'all ever build your own battery pack, please think about safety. Or if you don't, place a giant bucket of dry sand above the pack, with the bottom layer being made of acrylic or other plastic that melts. That's about the only thing that can stop a battery fire.
> place a giant bucket of dry sand above the pack, with the bottom layer being made of acrylic or other plastic that melts.
Honest question: is this a real hack that people do in these situations or did you just come up with it?
It's a hack I started doing after a friend's home almost burned down from a vape battery gone bad.
In any case, dry sand is one of the methods firefighters use to put out battery fires, the other being dumping it in a giant vat of water (that's what's done for electric cars) or class D fire extinguishers which are extremely fine powdered salt.
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He did and end run around saftey, and just put the whole system in a shed, which in any real emergency situation , dramaticaly reduces risk to life and property. Also each battery bank is.air gapped , which will significantly reduce any fire from spreading to adjacent banks. The system looks well made, and has 8 years up time. I live off grid and am useing lead acid batteries, but would like to switch to sodium.
The banks are "air gapped" by just a few cm, are all interconnected with excellent heat conductors (the bus bars), is insulated with flammable plastic, and sit on a flammable shelf in a flammable shed.
There is no fire safety there. Let's just hope the shed is very far from a house, fences, trees, bushes, or anything else that could catch fire and close any "air gaps" and cause harm.
Edit, digging in, each single cell is fused, very nice work, and exceptionaly safe to run. As good as anything built, anywhere.
https://secondlifestorage.com/index.php?threads/glubuxs-powe...
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From the article:
"Behind the success of this project lies an unwavering determination to overcome technical challenges. Glubux had to solve several problems over the years: cell balancing, electrical safety, and storage management. But his system keeps improving. For example, his energy production capacity has increased from 7 kWh to 56 kWh."
> with the bottom layer being made of acrylic or other plastic that melts.
Why is this bottom layer important?
If the batteries catch fire the acrylic bottom will melt and automatically dump the sand onto the fire.
This is a questionable setup though. You'd need massive amounts of sand dumped evenly, which requires more design and verification. Acrylic is also itself flammable.
A basic water based fire suppressor would not extinguish a battery fire but it will cool it and the room, limiting spread.
Let the experts design this kind of thing.
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If you don't have a bottom layer the sand will immediately fall
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Presumably so that it melts in case of a fire, so that the sand falls down.
Why is soldering a fire hazard?
Just curious.
Soldering dump a ton of heat into the cell, which has chances of destroying the cell. That's why most of the cells are spot-welded: its similar to soldering, but its much quicker and is localized only on the part of the metal that need to be melted, so the heat don't have time to reach the cell itself.
Taking a guess, probably has something to do with batteries heating up and solder having a low melting point.