High Amperage/Capacity battery pack Cell Choice consideration

[devrim6]

Hey folks, first forum post over here so I'm sorry for anything that I'll be doing wrong

I'm prototyping a battery pack for an electric race car and currently deciding between two major cell technologies: pouch and cylindrical. I've taken into consideration newer cells like the EVE 50PL or Molicel P60B, but as far as I know for pure pack density disregarding long term longevity pouch cells are superior. Other than Melasta, I'm not really familiar with pouch cell manufacturers. The inverter setup I currently use dictates around 210A in total for the 320V maximum they support.

My main question is: considering current and future (up to like 4 months from now), which technology would be better to integrate? Other than that, I have a few questions about pouch cell characteristics:
1. What can I expect in terms of size / capacity / amperage of a pouch cell? The packs I've seen using them looked very tiny.
2. Is choosing a higher capacity a sacrifice in terms of amperage or just in size? Melasta says their dimensions are custom, haven't reached out to them yet.
3. Are there any other manufacturers/pouch cells that perform exceptionally good?

Thank you!

 

[amberwolf]

You should look at used EV modules from places like GreenTecAuto, BatteryHookup, etc. First, to see some of the big ones with pouches, since you haven't seen these, and second because it's the easiest way to build a good-quality and safe and reliable big high current pack.

Regarding cylindrical vs pouch: Cylindrical have built in compression / containment for the layers, but pouch or prismatic, etc., will require containment / compression hardware. (see my posts about cell compression for examples / images, or look at large-EV packs).

There are also a few threads about big high current pouch pack builds you may want to look at, such as DogDipstick's, and JonesCG's.

Additionally, cylindricals are quite small capacity / etc, and will require many more interconnects vs large-capacity pouches, creating that many more failure points, variation points, etc.