Catellated Tesseract | Hummie Hubs V4 | Stewii Dual Escape | 12s4p 30Q | Psychotiller Enclosure

Hey man, I wish you the best and I hope everything gets sorted out.

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feel with you man!!! Just good that it didn´t happen in class and you ok!

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Could it be this…?

bateria1

Maybe they were cut but those nickel strips there?

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Its definitely possible. I thought I covered them with electrical tape, but could’ve been a victim of vibrations.

I could believe it. I had hoped the fish paper would be enough for that.

I’m really sorry to see your board catching fire, it was a really nice looking board, I’ve been there and all you think is “it could have happened in my house, I’m glad it didn’t” , but if you posted this on the forur, you might bee looking for answerrs on why this happened, so allow me to give you a couple of suggestions not only for you but for anyone looking to improve the safety of they packs:

  1. These nickel strip ends where rubbing on the circled spots:

image

They are really sharp and very easy to get in contact with the negative pole.

Here is another error: image

You should ALWAYS the corners like this:

  1. When you make a battery array as shown in your pictures, there will be a big leverage against the borders of the battery, negative pole, when ever the board flexes to the bottom or top, I always suggest to connect P-Groups with silicone wire, it will give you much more play on daily vibrations

  1. You MUST always isolate balance leads from cells, if they rub you will have fire sooner or later.

  1. You should ALWAYS use fish paper between P-Groups when mounting them in parallel and then stick groups together with silicone, hot glue or heat shrink so they don’t move and rub against each other, otherwise heat shrink and/or the original cell wrap will wear and cause a short.

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i just think that if the balance wires would be short, wouldn´t it just burn them out and good? I once shorted one blance wire, and it just burnded down in a millisecond without to damage the cell. but for sure the burned wires could burn holes in the cell isolation and start a big short there too.

Balance leads shorting could be one of the issues but my vote is for the sharp nickel strips rubbing against negative, second cause p-Groups rubbing against each other

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kapton won’t do much to stop abrasion - I use a combination of fishpaper stuck to 2mm foam for isolation

That’s a shame, such a cool board

My bet is also on the sharp nickel, in a traditional build that wouldn’t be a problem, but with a folding layout like yours it get pushed into the cell

A balance wire short can result in a fire, but since they are thin the chance is bigger to just melt right away acting like a fuse

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one layer of Bubblewrap on each side works too. it takes some space, but its awesome dampening :smirk:

It would be nice to have a thin plastic design (like Raptor 2?) to protect everything (main cables/leads/etc). Anyone have this design for flat packs ? 10s4p/12s4p?

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You used the balance leads that came with the bms, right? I think 24awg? And not silicone? I would think they’d self fuse before wrecking stuff…

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Since we are all here to check battery fault, now got me scared. I am going to make a 12s3p. I made this diagram, @Eboosted Could you please check it if it sound good for you? BatteryDiagram12s3p I have to follow this distribution because I do not have a lot of space. basically the last two P groups are on a second layer. I would have few questions: 1- I will use 10x0.15mm nickel strip, 1 is enough for the P group or better use 2 since I am going to connect the them in series with only the wires? 2- For series connections do you think 12awg or 2 16awg is enough or better on 12 paird with one 16awg. If I check only 12awg is rated for 41A, while 16awg for 21A. Isolation rings on the positive side and fish paper under the balance leads. Between parallel group I will use fish paper and also on top to separate it from the second layer. P groups glued together. Kapton tape on both of the sides of each 6 parallel group and foam in the middle to keep the two cell lines isolated.Then I will heat shrink the two layers separately and place the bms externally. I won’t use the cell fuse method because I do not have enough space in height to do it or maybe I can check it better later when I get all the parts. The enclosure is covered by foam around the battery and the battery is secured to the desk. What do you think about the diagram and the plan? Thanks a lot to everyone that wants to contribute. I uploaded here the pptx in case someone want to correct it or use it for is purpose :grin: https://mega.nz/#!ztknFCga!turUECUE_nF5vsvOhscW7wPgSiK21h_MCj-ENsBgXFw

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vibration Is the #1 battery killer, just having it sealed is not enough. There are many products available that will help reduce the impact vibration has. There are many ways to build a battery, and many have shared good advice and technical information. Just remember to be safe and understand what can happen in hopes of being prepared if it does.

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Got any pics? @rey8801?

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No that would be the plan for my new battery. I wanted to ask before build it.

I bought a cheap thin cutting board from the dollar store. Cut it and put between my P groups. Works great so far, along with fish paper and Kapton tape of course.

vibration I don’t think is a problem and u can vibrate all day but if ur constantly flexing it will strain the nickel connections and they need have some flex points with maybe silicone wire as shown or even a good fold point in the solid conductor, and maybe the foam for the vibration is more detrimental than helpful by pushing potentially sharp edges into cell casings

I use NESE modules and this is my way of dealing with flex and vibration. The downside is that I need a 7.5" wide enclosure to fit everything. And no one seems to have it :sob:
image

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