Yeah, I think in the photo where it looks like a double layer, the series connections get folded in half, so the pack is opened out flat. Interesting, first time Iāve seen that.
Thatās correct , each p group gets folded. Itās a popular method for the evolve replacement
No complaints. Maybe someone else can spot something?
On the subject of rounding the nickel strips on the positive endā¦ @PickSix24 - possible area for improvement?
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I was just going to say that ! I recall seeing that before but didnāt do it. Next build for sure ! Glad I put those stick on isolaters 
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Here is mine, its a lipo 5000mah 60c / 12s1p, ballance charged. Been using it for about a year so far and I use in torrential rain pretty often. Tropical country.
It has four 6s ballance plugs as its designed to have battery monitors permanently attached. Which I had for a while and I like the extra safety it provided but there was some issues, they only take power from two cells and will drain them over several days if you just leave the board. Also I didnāt waterproof them and they died a couple months ago. Now I just double check all the cells before I un-plug my charger.
The other thing that I donāt like about is I used 18 AWG balance wires and it was too bulky. And maybe its better to have something thinner that can burn up before the batteries do in a short circuit situation.
I opened the hard cases and filled the inside with epoxy for better water resistance and vibration control.
The reason it has two loop keys is so I can parallel charge it as one 6s pack. I use the one on the side as on off switch but have to remove both to charge it as a one 6s pack or it shorts the ballance wires.
My main safety concern is shorting out the wires on the metal enclosure. I have 3 layers of duct tape on it for insulation. Is fish paper waterproof? If so I may switch to that instead.
ā¦
After a year of use and plenty of water. 
ā¦
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I really only got the one response from @Battosaii and was wondering if there was some additional feedback from others. I think maybe my question got lost in the cell level fusing discussion.
Iāll admit that this has been my hope that with the super short lengths there is far less of an issue here but the last thing I want to do is kill my battery prematurely because the nickel strip is getting really hot during normal use. (when i ride I have a tendency to smash the throttle all the time lol really like the acceleration 
)
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Well thatās my understanding from doing my own reasearch.
On a side note I didnāt have any kapton tape and I found a local supplier in Miami 
they specialize in tapes and have any tape any size it was pretty cool. I got 2 rolls of 3/8" tape
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This is my 10s4p battery rebuild for the build I posted a couple days ago. That battery used cell level fusing, but I was careless and didnāt check for faulty cells, two parallel packs wonāt charge above 4.1 on two separate BMSās (also when charging each pack individually with an 18650 charger. So, I built a new one with cells that I checked individually, and I will recycle the cells in the original pack for another build.
This one doesnāt use cell level fusing, as it requires a bit more room the way I did it than I prefer (my Hummie deck cutout is the older narrower one). My future packs will use cell level fusing and will take up less horizontal and vertical space than even this pack. I did my best to make sure that the nickel strips wouldnāt be able to make their way under the positive terminals. The series connections are flat braided copper for flexibility purposes. Iāve had bad experiences back when I used nickel strips for the series connections so I moved away from that.
This is a gluing jig I made from laser cut plywood when I had access to my uniās laser cutter.
Gluing in action
All parallel packs glued up
Kapton tape insulation. I tried to mimic the way @Deckoz did his insulations on his 13s evo.
Top spot welds plus solder points (I scratched up the nickel under each solder point. How do these welds look? They seemed pretty strong, but I donāt have a frame of reference that isnāt my own. My other batteryās spot welds used the same settings or ever so slightly shorter pulses, and have held.
Negative terminal welds
Soldered the flat copper braid to each solder point. I wrapped the ends of each braid with kapton tape. I think the fraying would get worse with vibrations and make their way into the cells. Balance cables were then soldered, and connections were covered with adhesive back fish paper.
Here is the battery installed in the board. The cabling is messy, but balance cables are secured with kapton tape to the battery. Also I think soldering and heat shrinking balance cables to jst connectors is one of the worst parts about building batteries.
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Is there a reason why you used so big balance wires? Could you say me the size of the copper mash you used? Want to use the same but not sure what to order.
I used half inch ground strap: https://www.ebay.com/itm/1-2-BRAIDED-GROUND-STRAP-GROUNDING-TINNED-COPPER-FLAT-BRAID-MADE-IN-USA-PER-FT/302052799754?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649
That wire was the smallest gauge wire I had, itās almost as thin as the balance cables that came with the bms
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Never use duct tape or electrical tape for vibration insulation. Use fishpaper or plastic 2 liter soda bottle and polyimide tape if fishpaper isnāt available
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Oh, from the picture it looked like you just welded straight through kapton. Thanks for the correction!
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What if you did your square capton tape method then put a fishpaper ring on top of that? Your right that the rings donāt take well to the heat. You see some builds where it got carbonized. But capton is not as abrasion resistant as fishpaper.
@RHill051 At first I did not notice anything amiss. But after a second look I think it would be safer if you had some insulation between the P groups. Like one piece of fishpaper or something.
*Edit. Thought about this some more, its a little more complicated. If your glue never delaminated between the P groups it āshouldā be fine as there is no movement. If you did go add some fishpaper between the P groups it would introduce more flex into the pack which could create other issues. Maybe just an extra layer of Kapton between the P groups then glue like you have now would be best for your pack design. Somewhat like what @jasonbhuynh has done.
Yeah it sux that it makes the nickel bend down. I think button top versions are safer as it gives some additional serpation to the negative, but no one uses them as they cost more. 
Just want to add @TowerCrisis 's diagram here of how P groups could short each other if the insulation between them became compromised.
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Wow now I want to inspect my packs again 
@legend27 iāll link your question here, maybe somebody of the experts can give you a feedback
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