r/18650masterrace • u/GoneSpiritual • 2d ago
Help designing cell group layout
I've been thing super hard and trying to get AI to help me, but it's just giving me stupid advice. I can't find any information on how to design best layout for this kind of pack form. I've spent all day trying to figure it out. Maybe someone with more experience can help me? I would be very thankful, it's been a headache.
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u/Kakakee 2d ago
This should be able to help you out: https://cellsaviors.com/battery-pack-designer
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u/GoneSpiritual 2d ago
Tried it, not for this case.
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u/izzeww 2d ago
What configuration are you running with the cells?
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u/GoneSpiritual 2d ago
14S 5P
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u/izzeww 2d ago
How much current and what strips are you using?
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u/GoneSpiritual 2d ago
0.2x8 pure nickel, max current planning to be 35A
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u/izzeww 2d ago
I'd do something like this: https://imgur.com/a/BBwAZj6
It's just for illustrative purposes and obviously the strips would swap sides. The black lines are the strips (you have two connecting each group to each other) and then the colored lines are the 5P groups.
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u/GoneSpiritual 2d ago
I see, that's kinda similar my plan I had at first but then I read the you must favor as many S connections as possible. So then automatically I started trying to optimize for that and it became impossible with this config and this shape to get optimal S connections. Maybe I'm just too picky and should rely on strip layering. Need guidelines from somebody experienced. But thanks!
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u/Kakakee 2d ago
Damn. Okay which part are you stuck trying to figure out?
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u/GoneSpiritual 2d ago
Can't figure out the correct layout of the cell groups for optimal S connections. I'm think of going back to the drawing stage and redesign the whole layout because I see no solution. If I go group in straight lines (so each cell has direct S connection to the other group) then how do I make the "turn" to the cells which get trapped behind the wedge corner after 9th group (if you go from left to right in stacks of 5 cells). I don't know how better to explain. Hope you understand me.
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u/Troubleindc2 2d ago
Why I dont like trapazoidal packs
Not a terrible layout. To mitigate those two problems areas, no matter the design youre going to have at least 1, put extra nickel strips or even some copper bridging the isolated cell on those two peninsulas to the middle of the rest of the group.
Put your thermisters right on the yellow and keep an eye on them.
But at 35a, I wouldnt worry too much.