He wanted that bms because his ultramat lipo charger almost burned his house down…
He wanted the safest pack possible
Those over hanging edges are ther for a reason^^
They are the balance lead connections. I did it like this because there is no chance the balance strip could break off, like when it would be an extra strip welded on top (not that a failure there is that likely but whatever, it can’t hurt)
even if it’s k00ky… there is almost always a reason… thanks now I see why…
and honestly… I respect your and his wishes… my biggest trepidation after all this time… more that street-face… more than breaking my stuff, is actually charging my boards… after all this time plugging in a Chinese battery charger and hoping it doesn’t make fire is my biggest fear… add fuses… I do and it still scares the fukk outta me…
a decent lipo battery charger and no stUUpid BMS and fuses gives me zen and peace…
there are a million ways to do things… and I realize my way isn’t the only way… but you asked for comments…
peace brother!!! sk8 on
Do you know more about that?
Graupner usually supply good quality products.
Would be interesting to know how it came to it.
You’re right, but in this instance, he wired as discharge so bms thermistor monitoring will be a factor if his client is pushing serious amps
Where in EU can I buy the wide 0,2 nickel for 21700 cells?
Or is this one legit? https://www.aliexpress.com/item/32864017472.html?spm=2114.12057483.0.0.6f07527cEINp73
Yeah, Steel City nickel is good stuff.
What size strips are you using?
25x0.15mm usually
Should I be concerned with the voltage variance in this battery? 12s5p 30q, smart bms charge only, soft cutoff 3.3 / 2.8, I’ve driven it down to 2.8 once or twice, about 35 cycles on it, p-group voltage varies between 0.02 - 0.04 depending on the rate I charge it at.
25x0.2 worked great for a 21700 battery I just built. 30-wide would have been even better. Depends on your amperage needs and so on, but as nickel is not very conductive in the first place, I would prefer 0.2 over 0.15 if you have the option.
You are totally fine below 0.1V difference between the p groups. I would say even 0.2V is still fine as long as you monitor it and the difference isn’t getting bigger with each charge cycle.
it’s growing over time as expected as IR builds up, for some reason I had the 0.01V safety margin stuck in my head.
You can turn on Static Balance in the BMS settings and this will hopefully work its self out over time.
where is @ZachTetra our little tetris monkey?
I just happened upon a few P42As… 
@fessyfoo… I “might” need that nickel sooner than later…
It “looks” like it will fit… but she’s gunna be tight
12s4p, 4x4, dual receivers with canbus cables connecting the two closest boxes…
century 40 with eboosted enclosure
thinking about trying to minimize buss cable length and have the mains come from the middle of the pack but it’s making my brain hurt…
I have enough room at the side of the battery pack to run mains etc. Thinking about using @Scepterr’s 8mm bullets to connect JunkBoxes to the battery
NO room to stack anything…
while I’m working out this puzzle give this a look and see if you can make something logical coming out of the middle of the pack to keep battry buss lines equivelent… or am I just picking the flyshit out of the pepper mill…
They monkey is summoned!
If that was me I would actually do a separate battery, each half has a separate 12s2p and all you have is a common charge line…makes things a little more manageable
Basically 2 of these little monsters, making them is super easy and uses less nickel technically
except I’d need another 12s BMS…
this makes too much sense… there has to be a flaw in your logic…
thanks for your thoughts
If you want them coming out of the middle, make the battery a giant C shape with the ends at the center along a side, then you have a T for the pos and neg that run to the escs
A little nasty but certainly reasonable…it will try and current throttle a little but if you use 2x 10awg as the series connections and then have the split for the front and back on the nickel it should be all good
not necessarily.
you can connect all the balance leads from the two packs and into the one BMS. but now your BMS leads are uneven… lol.
my first BMS was wired so that every cell had the same length lead to the BMS. what a mess. definitely picked a bit of fly shit out if the pepper myself on that one 
