is that 3/4" braid? I got some, works good, nice work on the soldering thereš
1/2" would have been enough and marginally cheaper. But YOLO and allā¦
No this is 1/2", Iām gonna order some 6mm stuff though
Yeah I understand the tradeoff. Iām hoping to be able to take the modules on a plane as they are all under the flight limit.
edit: I decided to go with no BMS and just stick a 5pin automotive connector on each module.
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Lol, thats crazy. Why not cut the braid down so it spans from the middle of one group to the next?
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ā¦I want it to look pretty? I want to sell batteries through the next couple years to pass the time stuck with online classes and try to even out the prices on some of the parts I bought, this is the example pack so I really want it to look good
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Which now means youāll be stuck using that size braid and length on every pack. When a battery is sealed, I refer to the builders example pack
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IMO it would look prettier with the braid landing in the middle with a small solder puddle just at the end of the braid.
If your intention is to solder to the whole bit of nickel, youāre gonna have a shit time and end up with a stiff series connection.
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Haha but you see, thatās where youāre wrong, if found a way to make the solder joint look like a professional TIG weld yet thereās only a little bit of solder wickā¦still hella flexy!
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Fair point, Iām gonna take pictures as I go for each pack (liability reasons) so there will be an understanding for whatās under the wrap
What do you guys recommend for separating the end to end parallel groups? Is a layer of fish paper good enough?
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I wrap mine individually. Especially in a flexy setup. But Iāve used partial pieces between P groups in some.
Glue, fiberglass tape, adhesive fishpaper
So how many layers between the nickel? The can to can contact has a layer of paper and heat shrink on each
Iām thinking Iāll have a strip on each side so itās just the paper that makes contact with another piece of paper, all the nickel is rounded so itās pretty smooth and flat
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On the 21700B cells I built a pack with recently, any where that I had a folded connection or a positive terminal that had to come over the edge, I would build up to the top of the positive terminal.
For those, I used two of the fishpaper rings on each cell. I try to build the fishpaper up flush with the top of the P terminal so the nickel is bending straight from there. Less chance of it getting to the cell body
For the sides, i think if each P group has a fishpaper later youāre good. Ideally itās fishpaper against fishpaper.
I put a dollar store cutting board in that mo-fo
Thatās a hot spot right there
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Haha, I think Iām a little short on width for that 
Ya good idea, in mine I have some of that yellow hardboard stuff that they use in production packs laying around, no horizontal vibration is making its way through that.
Thats neat 
would love to know the process.
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Metal everywhereā¦I have 3 different heat sinks, maybe 2 lbs of steel mass and 20 in^2
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It sounds tedious 
not to be a killjoy, because it does look great, but is that a viable way of building (time wise) if you are looking to capitalise on building batteries?
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that just makes me more curious. got a picture of the heat sinks in place.
those solder joints look like welds. now Iāll be even more confused when someone says welds vs soldering. 
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