Kapton is fine for protection and some structure, then shrink wrap it
What’s the problem?
do you c the erosion under the balance lead in the pic… pondering on how to handle it i think there might be something affecting the pac
Heatshrink it?
you mean on the cell? Looks like a standard weld to me
ah ok good… wasnt sure it looked suspicious…
Yah I’m not seeing anything particularly wrong
i was getting on it, and it was cutting out at wot could have been just a low battery kind of thing i guess, maybe i was trying to accelerate too much
What cells are they, how old?
30q, maybe 8months… definitly had some serious down time also, usage is split between a secondary pack, as i was alternating after each ride
That’s not old enough to have any affect, I would check that all the cells in each P is welded, if not you could be getting proper voltage but less range and bad sag Just check the voltage on each cells positive and neg terminal, not the nickel, if some are loose they’ll have a different voltage from the rest
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should i fire up spot welder =)
ya long ass time since i started this… i feel the guilt trust me! Had school relocation, and a gauntlet of problems to overcome, even almost had to quit eskate… but hey here it is, and im GOING to finish it…By the way that 12s2p blew the rear series connection, the cuttouts i had were from the focbox resetting most likely. it was crazy 2 c that i melted the dc pigtail but the cells are still good i think =)
So far, ive managed to build 2 packs each containing 6 series connections… im still missing some information however, im emulating @stimm 12s4p build as closely as possible. i am aware from @b264 that ive made some mistakes, and hoping to rectify and share the information I get. i got some really good info from @Deckoz and should be able to finish all the welds by next week. my welder isnt performing well with 2 sheets of nickle, however i will have to do even more welds to account for that. after next week if all goes aaccording to plan i should be able to figure out the balance/phase wires and do my main terminals.
all tips, comments, and help is welcome here 
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Got the left pack done. Probably should have charged the cells before hand so I can verify the pack voltage. But guess I’ll let the bms sort that junk out… might run out of nickel strips so I’ll probably order some tomorrow, had to do a couple of additional passes with spot welder. The more I stare at my 12s2p the more similarity I c between them. Probably will just follow the balance lead orientation for that one. Need to figure out switch main leads and charge situation that will most likely be harder than the balance leads. More to come soon.
Is it chill to bridge the 2 packs with xt90. Slightly concerned with connecting the two packs together so that’s why I would like to use the xt90. I don’t like sparks, and my chest already hurts 
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I’m actually building a 12s4p with the same layout.
There will be no sparks making the serial connection. If you don’t short anything that is.
You should double up on the nickel on the series connection if you are using 0.15mm. Shouldn’t say should, but I am anyways 
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your welds look good, mine are barely useable. id like to see where ur putting your series if u get a chance later. maybe after english class today I can get that other pack done… crossing my fingers
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Sure, will post as soon as it’s done. Waiting for more cells from nkon.
my balance leads are very tiny wires, any chance u know what to put on the ends of them to connect them to the battery