to gain about 1/2 inch [12-13mm]. Stay tuned for cell layout mockup photos… I’ll ask more about nickel then. Planning 0.2mm nickel, leaning towards cutting my own nickel to achieve full-p-group-width foldover vs. the precut shapes which tend to neck down the x-section of the folded over portion.
Got a fat car battery to run the Malectrics And extra cells for weld pull tests to dial in settings & technique.
Yeah! I have studied your write-up more than once… and will go back to it again I’m sure.
Just did something very similar to this and im working on a write up of how i did my gasket but probably a week until im finished. I did an 18s6p configuration and ended up with right about 9mm of gasket total… but it was a close thing.
I had to reconfigure the cells nearest to the center rib because the board flex pushes further into that are because it’s the flattest section of deck.
My enclosure looks to be a slightly larger version so i was able to fit three rows of 8 cells in each bay with a stagger stack of 6 cells on the outside rows - leaving the center row for wiring and the deck concave.
I did my gasket with hard neoprene - glued to the enclosure with butyl - and a thin layer of neoprene foam over it to clean it up and let it compress a little.
If you have a router with a guide bearing on the tip of 3/8” blade cutting the inside profile is pretty easy - just go very slowly - and make sure the rubber is very securely attached to the enclosure. Butyl and a lot of cleaning with iso is the only thing I could get to hold up.
I found cutting the outside after attaching it to the deck with a sharp razor worked best, and you can hide the cut marks by going over it with some 120-220 grit sandpaper - trying the router had me redoing sections because there is no good guide line and a quick slip will ruin everything.
If you bias the cells to the outside as much as possible it will get you more clearance
Wow @Pecos – this is next level stuff! Super impressed with packing in that many cells.
And the gasket construction is a thing of beauty. When I get to that point your methods will be surely be emulated. Thanks for sharing all the details about materials & tools & techniques
You might be able to get away with less gasket height (and therefore buy yourself more more ground clearance) by 3d printing cell frames for those p-groups that spread the groups out to the maximum width in the enclosure, rather than going for a tight stagger stack like you have in this pic.
@Ac53n’s Split Decision thread shows this strategy to great effect.
@nclayton if you’ve got any questions i can show you how i designed the pack for my build, you should definitely be able to slim down the battery a good bit by changing the stagger setup. the link should give you a rough idea of what i mean by that. Cheers!
I knew you guys would have clever ideas like this. @Ac53n – your cell holders are neato!
Gonna fiddle around in CAD this week to explore the benefits of spreading the stagger looser. Optimizing for the Barrel enclosure + deck concave.
I really wanna go 12s7p and feel its worth the extra effort and added gasket (if <12mm). However every mm of ground clearance matters. 12s6p may work in the stock enclosure (w/o adding gasket) so that’s tempting but feels like the easy way out.
Still haven’t decided which way to go 5p is possible with minimal added gasket height…but sub-30mile range doesn’t quite sit right. If going to 6p, why not 7p (for +3-4mm height penalty)?
It’s amazing how much the deck concave eats into enclosure space! I can imagine many batteries have been built with planning and good intentions… only to find out they dont fit height-wise
That’s why my custom enclosure and pack is designed to conform to the deck as much as possible
Its also shallower at the edges to give more clearance during turns, as thats just wasted clearance if you dont. Kinda surprising just how un-optimal some of our stuff is
If you’re willing to modify or make your own enclosure, you’ll be able to fit more cells while still having similar or better clearance.
Something else to consider, the pack doesn’t need to be symmetrical from side to side.
If i were you, rather than trying to model 7 cells to fit in one side, i’d be modelling the 14 cells to fit across the entire width. That space in the center can be shared
7 P30b vs 5 p45b - no advantage but it costs a bit more to do 18650s imho Maybe some other cell would math better?
How big are those circles? Cell sized or are they oversized to accommodate insulation and padding and real world tolerances? 6p would probably be the least worst for a gasket and get you in the range of 20miles (at a hard ride 45wh/mile)… with a p45b. After all the fudging probably closer to 17-18 full send?
I say (biased opinion incoming) if you want range as your goal and want to use the enclosure you have without looking around for a deck/enclosure for a loanstar to slap on there instead - go for broke and do 7p. When you get your gasket material bias your choice to the slightly larger of standard thickness and make or buy a stiff riser of the same thickness or slightly less at the same time. If you weren’t happy with the range before but a 10-15% boost would make it worth the effort go 5p to make it a quick easy project.
And extra cells for weld pull tests to dial in settings & technique. 
When I get to that point your methods will be surely be emulated. Thanks for sharing all the details about materials & tools & techniques 
5p is possible with minimal added gasket height…but sub-30mile range doesn’t quite sit right. If going to 6p, why not 7p (for +3-4mm height penalty)?
