There is fishpaper between the ppacks but only where terminals touch in the picture below there is fish paper where itās red but not where itās blue.
the blue one was my question.
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Where the blue is there are no terminals of the battery so nothing to touch and short.
but itĀ“s the place where the battery flex. because of this flex the packs can rub on ech other and damage the thin plastic cover around the cells. as you for sure know the main part of the outer cell is the negative pole. so if two packs damage there isolation next to each other over time you short your packs.
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@Andy87 Thanks for pointing that it i will definitely take that into consideration for future builds and possibly add some fish paper there on this one. however there is kapton tape over the positive cap and there are 2 layers of shrink wrap one over each of the parallel packs that fold inward a bit and covers most of the positive cap and one over the 2 parallel packs that are next to each other so the chances of it shorting that way are very slim.
Andyās talking about the cell bodies rubbing together and wearing through the insulation. Cell bodies are attached to cell negative.
Heās not talking about the caps/terminals.
Fish paper is more abrasion resistant than kapton or shrink wrap.
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@deucesdown I get that but the main problem would be the positve cap touching the cell body which is negitive but if the positive cap is covered it cant short on the negitive cell body.
If you have a connection from positive on one to negative on the next group in series, and the wrap wears between those groups, the cell bodies contact and essentially short positive of the first through the negative (body) of the next which is the negative of the first. Itād be like shorting positive to negative on the first group directly, just via the cell bodies.
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Issue still remains I believe because the cells that are stacked āfurtherā into the series donāt actually have 0V on the GND side they have all the voltage from packs before them.
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@Andy87 @deucesdown @wafflejock There is a very slight chance this will happen but just to be safe i will add fishpaper in this area on this pack and in future packs!
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This is worth reconsidering. Imagine what happens if you connect cell negatives of two touching P-groups together.
The chance may or may not be slight. The consequence is pretty serious.
Iām only harping because this is the āreview my packā thread! 
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Awesome result guys, potentially saved a burnt down esk8.
Its not obvious at first but p-groups can short each other out across the negative outside can via the nickel strip that joins the p groups. If the thin shrink wrap gets damaged from vibration etc. Shown in this diagram way above on post #65
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How many strips of 15x0,2 nickel would be needed for P conections, then series are done with tinned copper. 4p being up to 30a each. 3 strips?
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unfolded lipos are missing there!
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This depends on where and how many series connections you make and how many max amps your system will draw (building for 120a draw with nickel will be a bit intense)
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Awesome! I have a special folder on my phone for all the battery packs 
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My original idea was to use this type of nickel, using one thick tinned copper braid to make series from one pack to another. Max Iāll ever draw will be 100, but numbers like that rarely acure. I was thinking of maybe spot welding 2 extra strips on top of this one.
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If i see that I could imagine you sell battery packsā¦ crazy no?! 
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