You gotta’ appreciate their eco-friendly use of those black foam scraps in the “top”. 
Sheesh…what a mess. 
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I think I’m gonna be sick if I keep looking at that 
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Question pls.
I’m building a 14s3p battery using A123 cells.
For the P groups I was going to use 8mm x 0.3mm nickel strip which the seller has rated as 50amp. (Is this over kill? For the Series connection I was going to double the same strip up so 2x 8mm x 0.3mm
Any help appreciated. Thx
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2x 8x0.3 is good for 45A and wouldn’t recommend past 68A
In parallel a single strip is more than enough, if you’re making a brick pack you wanna do the series strips first then the parallel over top
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Thx. Can I ask why ?
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Check out this thread on current ratings:
Series connections do the heavy lifting with respect to carrying current in a battery. Are you building a brick pack?
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Yes. I’m building a brick pack that’s going in a small peli case
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If it’s a brick pack, you’d be better off sourcing some nickel sheet rather than 8mm x 0.2 or 0.3. First, the latter is a bitch to weld and may cause problems down the road w broken welds. Second, it will run hot even if you double up your strips. You’re better off sourcing some 40mm x 0.2. It’s pretty easy to find and is sufficient to carry your current provided you orient your pack as pictured. (Arrows indicating flow of current).
18650 club sells sheet that you can easily cut to size as well:
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The batteries I’m using are 26650. Would I not just be better using like an 0.8x0.2 m for the P groups and then a 12awg for the series connections?
I find the big strips covering multiple cells dangerous as u can’t see where youre welding and by mistake you can weld the negative ring outside the positive center and then they’re locked in a short and can be really bad
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You can make a guide from fish paper rings, laser cut fish paper, or 3d print one
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You can also rub the nickel with the back of a screwdriver to imprint the cells on it a little. It’s visible under an angled light
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i used the butt of a sharpie for this, worked great
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Lots of good tips here. I personally use the handle of my wire cutters which is high density foam rubber and works nicely to outline the pos terminal.
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Adjust your width accordingly for the nickel. With a brick pack, making series connections w silicone wire is not done bc it’s impractical. Half of your wires would be under the battery with the weight of the pack on top of them and vibrations stressing your joints. I’ve considered braided, tinned copper for this as it lies flat but nickel is easier, more practical and more-than-sufficient to carry your current.
Unless, you were you use holders and have the cells lying on their sides. I’ve not built a brick out of 26650s, but it’s only an extra 10mm from center to center so 40mm should still work imo and if not, buy a sheet of 200mm and cut to your needs.
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I take my incredibly thick skull and bash it into the battery pack, no problems so far
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So I have a pack made from SKP and after my last ride I noticed that p-group 12 will fluctuate resting voltage quiet heavily. Most the time the p group is right in line with the other groups voltage wise but it will sometimes drop by almost .2 for a few seconds before going back up to normal. Idk what the problem could be or how damaging it could be to a pack that’s only a year old.
Have you checked the connections for the balance lead? My guess is a loose connection at either the solder joint or the harness. Check both, unplug the wiring harness and make sure all of the dupont m/f look ok and then make sure the harness is firmly seated when plugging back in. If everything else is gravy and the reading keeps fluctuating you may have a bunk bms.
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What do u do with the balance wires that are underneath the pack though?
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That looks like possibly some welds have come loose mate 
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