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LiFePO4 Enclosure? Safety?

aaron_c

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Jun 18, 2020
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After reading this article about Lithium battery fires, I came away with the impression that LiFePO4 batteries should be encased in some sort of fire-resistant enclosure. Honestly I'm kind of fuzzy on this, they had a picture of some kind of bag.

I gather there's also the issue of protecting the battery leads from short-circuiting, which, depending on what conductor is responsible, could also cause a battery fire iirc. (This from a Prowse video).

But in spite of all this, I don't see a lot of discussion of battery enclosures. Do yall use them? If so, where do I buy one of them or how do I make one them? If not, why not?

Thanks so much!
 
After reading this article about Lithium battery fires, I came away with the impression that LiFePO4 batteries should be encased in some sort of fire-resistant enclosure.
That was a crappy article in regards to LiFePO4 which is a pretty safe chemistry that does not catch on fire.
The cells will puff up and vent when overcharged but I have not seen a video where they catch on fire.
LFP can be punctured and not catch on fire.
Other Lithium ion chemistries are dangerous for sure which is why most solar systems in houses or mobile do not use them.

Short circuiting a LFP or any battery will make big sparks and heat that may catch nearby flammable materials on fire.
 
Thanks @MBR, that's a relief!

Does that also mean that most folks here won't be using a battery enclosure unless it's something to do with temp regulation (like to keep the batteries warm enough to work on a cold night)? Do people put something over the battery contacts just to stop accidental short circuits?
 
LFP chemistry is a much safer chemistry but they can only take so much abuse. If you are using a BMS, your risk of fire almost nill. with additional fusing in the rare chance of something else failing again lowers your risks. I am using a polymer 'ammo' box that I bought off amazon for a 12v 400ah battery in a 4p4s confiuration. It weights in at about 95 lbs and is fairly easy to handle.


So far, the case is showing signs of termal insulation which is good. the cells are staying very close to average ambient temp or a little cooler..
 
Thanks @MBR, that's a relief!

Does that also mean that most folks here won't be using a battery enclosure unless it's something to do with temp regulation (like to keep the batteries warm enough to work on a cold night)? Do people put something over the battery contacts just to stop accidental short circuits?

That is why I use a case. After building the battery, even the cell that have covers like mine are still somewhat dangerous to have exposed.. a single tool being dropped on them will create a crazy lightshow that will rivel silverware in the microwave. There is enough energy there to weld a 1/2" steel shaft in a few seconds so I don't mess with it. I want to keep the cells safe from other things that can cause shorts. I want to keep the humidity and temerature as stable as possible so when it gets to 100% humity and 95 degrees outside as it does in FL, I don't want the cells heating up.

The case should protect the cells and me from fireworks.. A single screw dropped on the battery can be bad..
 
I retired from the electric power generation industry. Think 850MW electric generation. Many plants had back-up battery banks to power specific equipment in an emergency. very high amp-hour rating and high voltage, series and parallel connections. Battery rooms were locked, entry required permits, special pre-job briefs, tools were wrapped in rubber, were non-conductive, rubber tarps were placed on top of batteries when being maintained, staff were specially trained, pockets were emptied, and any personal metallic “stuff” did not go in the room, etc. Safety was paramount. All jewelry was removed. One person objected to removing their wedding ring, result was they did not enter the room. The plant equipment was placed in certain operating conditions when battery maintenance was ongoing.
Moral of the story - keep the magic electric smoke and sparks where it and they belong.

Now that I am “playing” with multiple batteries with larger voltages and currents, I am glad I had that training.
 
Thanks @MBR, that's a relief!
.

LiFePO4 (also known as Lithium Iron Phosphate) batteries are a huge improvement over lead acid in weight, capacity and shelf life. The LiFePO4 batteries are the safest type of Lithium batteries as they will not overheat, and even if punctured they will not catch on fire.
The cathode material in LiFePO4 batteries is not hazardous, and so poses no negative health hazards or environmental hazards.

Due to the oxygen being bonded tightly to the molecule, there is no danger of the battery erupting into flames like there is with Lithium-Ion.
The chemistry is so stable that LiFePO4 batteries will accept a charge from a lead-acid configured battery charger.

Though less energy-dense than the Lithium-Ion and Lithium Polymer, Iron and Phosphate are abundant and cheaper to extract so costs are much more reasonable. LiFePO4 life expectancy is approximately 5-7 years.
 
I saw the pic of the case above and was surprised. I just completed two batteries using that case. Heh. I need to make two more and was considering using that case again, however, I would also use the battery pack as a step (in an RV, any space is valuable). I'm considering building a box out of 3/4" ply, maybe 1/2", coating the interior in epoxy. I know the idea of "wood" isn't the greatest, but hell, if a battery goes nuclear, it's going and any box in that confined of area will not stop the destruction.
 
From reading the comments, the main consensus seems that the case/box is basically just protection from something creating a short..
If so, could something like this link also be used
https://www.amazon.se/dp/B07ZHD5TQ1...t_i_EMJ5ACS212ZZ1XSH13MS?_encoding=UTF8&psc=1
If you don't want to click, it's a travel suitcase on wheels, with an opening for laptops, which could be modified for an access panel.
Most likely a frame would be needed inside to hold things together.
Then my thinking gets starts considering securing it to the RV.. hmm, obviously not with the wheels at the bottom. But maybe the chosen bottom, could be mounted to a theoretical inner frame/ support!?
Or am I playing with fire?
These seem readily available, portable, and fairly well priced.
 
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