Haha, I think most recently has been me. I found their use thru Dr. Mike tho.
To call them sergical tools is a bit much.
2 Likes
Cheers for the hot tip! I love it!
1 Like
@b264 add this to your repository.
UL 3135 aka Stranded Silicone Hobby Wire spec
The Chinese part is obviously the ampacity
4 Likes
builders,
I’m contemplating building a pack with Moilcel P42A cells, started to work up a BOM to assemble parts etc. and went to check on nickel amperage limits… holy faak …
at 45 amps each cell what are you guys using to assemble the P-packs?
Given that .3mm thick nickel is problematic with a K-weld… I realize I’ll have to build in a heavy buss bar-ish for the series packs but I can’t wrap my head around how thick (many) nickle strips I’m going to have to weld on for 45amps…
suggestions please…
7 Likes
These are a guide only… i believe you can very safely add at least 50% onto those values without an issue.
Remember that most ratings are for that current over a 1m length of material. As our material length is a lot shorter than that, we can safely get a little more out of it.
Also, just because your cell is rated at 45a, doesn’t mean thats how much you are going to be pulling from it continuously.
5 Likes
Understood… mostly it’ll be a cruise mode fun board… but I do plan on stoplight to stoplight drag racing… pulling as many amps as she’ll take for 5-10-15 seconds…
what is your suggestion for P-pack nickle strips?
3x .2 x 10mm strips?
3 Likes
The strips across the p groups don’t necessarily (and very rarely) need to carry the entire series current…
Gimme 5 mins, i’ll draw you a picture
3 Likes
Lets assume you have a 5p pack. Each cell is pushing 10a each.
The current only wants to get through to the next p group in a discharge situation, so depending on your series connection configuration, will determine how much current the p group strip sees.
In the configuration above, there are only 2 series connections. That means those 2 connections are trying to pass the whole 50a to the next group.
The p group strip only needs to deliver the current from the closest cells to the series strips. You can see that the strip either side of the center cell is doing less work, as it can deliver half its current to each side.
comprende amigo?
12 Likes
while you were drawing your pik I was drawing one as well…
at 12S2P i’m going to have a 90amp pack 45amps possible to the series buss…
3 Likes
In a 2p group life gets a little simpler 
5 Likes
and yet my question remains…
given this construction what are your welded nickle strip recommendations…?
Your suggestion relies on those 3 pieces of nickel being a solid unit. In reality, you are only going to have a stable connection to the top layer of nickel
3 Likes
I would join the 2 cells with one strip, and then give each cell two tabs. The tabs should come away from each cell not directly on top of each other, but slightly separated so that the solder from your series connection can be in contact with all 4 tabs
2 Likes
Interesting suggestion, I’ll take that under advisement… but back to your solid unit of nickle… how about if I weld the nickle strips together under where I make my series connection… would that not make my nickle a more homogeneous unit?
1 Like
It would be fine if your series connection came from on top of one of the cells but it would be tricky to weld the center of the strips.
It would suck to weld the center and accidentally weld into the negative cell casing 
3 Likes
I tried this a couple times with used cells, 0.2mm nickel at 55 joules on the second layer, the fish paper charred a couple layers but the bottom facing the cell didn’t discolor at all. I think if you blow through both layers of nickel and the fish paper your settings are probably way too high
2 Likes