DIY modular packs, Single Cell, Parallel then Series, or Series then Parallel?

[Shale MacGregor]

It basically breaks down to Pros and Cons, hoping for someone to fill in the blanks. (These are cylindrical cells so positive on one side, negative on other end)

14 cells in parallel blocks, then blocks connected in series 16S, 40kWh,

Pros: No shorting terminals
Batteries self-balance?
One BMS for entire setup


Cons: Thicker Wires (500 amps @ 3.2v)
Single point of failure (block) reduced energy of system when hits low voltage early
Can't add storage easily (18s max)
one weak cell brings down the entire 14p16s setup in terms of energy



14 cells in series blocks (14s), then blocks connected in parallel (16p)

Pros: Thinner wires (35 amps @ 44.4v)
Easy to add on to pack
One block failing reduces total energy but doesn't bring system down

Cons: 16 BMS (Cost, complexity, another point of failure but with redundancy)
Terminals easier to short


After writing it all out, it kinda seems like a no brainer

 

[MisterSandals]

14 cells in parallel blocks, then blocks connected in series 16S, 40kWh,

one weak cell brings down the entire 14p16s setup in terms of energy

and

14 cells in series blocks (14s), then blocks connected in parallel (16p)

One block failing reduces total energy but doesn't bring system down

I think you have this backwards.
One weak cell will not (greatly) affect 14 cells in parallel.
One weak block will not (greatly) affect 16 blocks in parallel.

 

[Shale MacGregor]

and


I think you have this backwards.
One weak cell will not (greatly) affect 14 cells in parallel.
One weak block will not (greatly) affect 16 blocks in parallel.

Yup, I was thinking of it wrong, thanks!

 

[Boondock Saint]

https://diysolarforum.com/resources/cell-configurations-for-12v-24v-and-48v-lifepo4-batteries.42/download

 

[Shale MacGregor]