It’s just padding so that the NESE modules don’t press against the balance wires. Otherwise the insulation on the wires could easily get damaged, which would likely lead to a short circuit across the balance wires.
And yes, it’s 12S4P.
1 Like
These spots make me nervous:
It’s just too close to a short. I know that things probably can’t move there so it should be fine. I would still put at least a piece of fishpaper or cardboard or whatever to create some separation.
@Agniusm Would it be possible to make a version of the 2S4P housing with the separator on both sides? Seems like an easy modification and would be nice for these 2x 4P setups.
2 Likes
I have been riding over some semi offroad street with rocks and potholes in my streetboard setup and there was no short. The packs need to brake and be pressed together to generate a short. I just don’t see it happening under normal use. Normal packs can also short in a crash so i wouldnt panic.
I’m not panicking. Just saying you have two unseparated points in a circuit there, maybe less than 1mm apart, that will cause a dead short if connected. It worries me. Probably not that much of a problem when riding since once you press the lid on, it’s pretty much impossible that anything will move unless there’s a serious crash. I would be more concerned about servicing the pack, e.g. replacing a bad cell etc. That’s when things can move and the short is just too easy to happen then.
1 Like
It worries me too. So I use my own boxes with gap in between.
1 Like
Got a link please?
It’s in the second post. I don’t know if I have put all my models there though. I’ll have to check.
If you are looking for anything specifically I can quickly edit and share. I probably may even have it.
1 Like
Is it this one?
There does seem to be a small gap in the middle. Does that still work for 2S4P modules? And if not, is there a reason for not just making the separator on both sides?
Wow very nice work. Do you have final dimensions of the pack length / width? What enclosure are you utilizing? If it is mentioned above just missed it…
You have nothing to worry about. There is 0.9mm gap with separator and for your peace of mind you can fold some fish paper and insert where separator slopes.
But if you could imagine that with the lid on each cell sits in a cradle and cant move anywhere. I mean you need to smash it completly and even then there is high chance that cells will fall appart untouched from impact?!!
I cant make barrier through the whole length as i need to insert full tab and having another model for 4P+4P is just not worth it as there is no risk. I can assure you that it wont short unless badly damaged with and with anlot of luck for short. Even then it will be least of your worries 
3 Likes
Trying to minimize any chance of a short since the pack isn’t fully integrated yet. Also, the enclosure is narrow enough in the middle that the caps do not quite fit (which is why the caps at the middle of the pack are missing). Love the fit of those caps btw. Not sure what filament you are using for these but they have the perfect amount of give to grip the bolt heads.
Haha, that’s quite true.
Good question, two reasons.
First, the ends of fuse itself are slightly smaller than the distance from the m5 bolt at the edge of the pack to the edge of the module. As such, the fuse casing would impact the module material and not be able to bolt flat.
Second, the casing on the middle fo the fuse is a plastic non-conductive material, but certainly not load bearing. I’m getting around this using a short bus bar at the pack edge, then the fuse, then the lug. The entire thing is wrapped in 1/2" heat shrink, which lends the rigidity needed to keep the fuse in place without strain (at least that’s the plan)
Here’s a shot of the unwrapped lead:
3 Likes
These do work for 2s4p. They also work good for 2x 1s4p. I used these to make my 12s4p pack. The divider in the center holds the cells apart well enough, I dont think that its necessary to be all the way across.
I used 21700s and scaled the model up, which resulted in the walls being thicker than they really needed to be. Still, it is much smaller than the original box.
@mishrasubhransu any chance i can sweet talk you into designing the boxes for 21700 so that im not loosing 6mm to wall thickness? 
1 Like
I haven’t measured it yet, but will post it to my build thread soon. A full Bill of Materials is linked to from that thread as well.
30% OFF, code: smallisbig
on 2P and 3P (including 2S2P, 2S3P) modules, also hardware kits (manual discount, refund after order)
expires 01/06/2020
4 Likes
Looks complicated. Why not just use 8P enclosures and awoid all that wiring nightmare? Only tging it will have power output on opposite ends. You can make flat bus bar out of copper and some heatshrink.
You can even use 2s4p to double up series busbar for more current.
You need to utilize whats inside to have as little as possible outside
3 Likes
I don’t understand your notation what’s 7s8p?
Looks like 7th 8p group. I agree the notation is unfortunate.
1 Like