We've been making pint quart batteries wrong this whole time.
In a pint, the usual 21700 15s1p "quart battery" (as made popular by chi battery systems, see last photo a la board garage) is a 7s longitudinal layout closest to the BMS, with a wonky 2s that is out of +/- phase on the board's left, followed by a 6s in a 3/2 lateral layout near the tire. I find this to be... Needlessly complicated? The 7s longitudinal layout is slightly wider than the 6s 3/2 lateral layout, but it is typically placed near the BMS where the battery tray actually narrows slightly. This makes fitment poor, and the terminal flow requires a switch up that is generally done with wire to get the final terminals in roughly the correct location. The end result fits poorly and requires some serious muscle to cram in, and often requiring some cutting/grinding of the battery box itself. Anybody who's crammed a chi quart in knows what I'm talking about.
Behold: the logical quart. This fits, and in fact I used 3mm neoprene at the top and a sheet of 1.5mm neoprene above and below the pack- so it even fits with room to spare. No muscling the pack in, no grinding dividers. This is an easy fit, no-cut battery solution other than trimming the BMS cover (the balance wires still exit the pack higher than stock batteries because they're taller cells)
Basically, why are we shoe-horning in the 7s long section into the narrower part of the box? Moving that to the tire side and bringing the better-fitting 6s 3/2 lateral section toward the BMS results in much better fitting and much more logical terminal flow. In my layout, the nickel strip for 6/7 (ha ha) is a simple right angle instead of a lengthwise jump of wire for the "usual" battery's 7/8 connection, and while you could also do the section of wire jump for 8/9, it is also a pretty simple bend to do with nickel.
The downside is final terminal wiring. The overall pack positive and negative terminals are literally right next to each other. Instead of attaching the positive wire directly to cell 1 and having the negative wire millimeters from touching, I opted to extend the positive terminal away from the first cell. 3 layers of kapton and 2 layers of fish paper went on top of the 4/5 nickel strip in alternating sand which fashion, and cell 1's positive terminal was extended to sit on top of cell 4. The positive wire was soldered on and heat shrink was applied, making 6 layers of insulation between the final positive terminal and the negative terminal under it. I also did the 3 kapton, 2 fish paper cover up job on the positive terminal of cell 1 proper so the heat-shrink-covered negative terminal of cell 15 similarly would be well insulated from exploding.
My layout also let me use fish paper between the 1/2, 3/4, and 5/6 cell groups as well as across the rear of the upper 7 run with ~4mm to spare length wise (thus the 3mm neoprene on the finished pack). Width wise, that run of 7 still near the tire barely fits so no fish paper there, but I was able to add kapton tape to the side of every cell for a little added insulation instead of relying purely on the wraps, then gluing it all together.
TL;DR: the old quart battery layout is more complicated and worse fitting than it needs to be. Try this instead.
