I DIY all my battery packs with prismatic LiFePO4 cells.

I’ve used various sources over the years, but right now these are my top picks. Try to go for 304Ah or bigger cells. They tend to have the best price per kWh right now.

If you want them directly from Chinese suppliers, I’d go with one of the following ones.

Unless you know what you’re getting into, stick with the providers mentioned in the first list. That said, if you like to take some risks – there are quite a few vendors on Alibaba that sell these cells at rock bottom prices. Keep in mind shipping terms (always go for DDP Incoterms unless you know what you’re doing), but it is possible to get cells (that test actual capacity) for under 50 USD per kWh right now. I wouldn’t make an EV with them, but for solar storage, they’re definitely tempting.

While I put my cells on a shelf with my own compression frame, the trend currently is to put these cells in a DIY battery kits. There are quite a few available, some include a BMS.

While I don’t use them myself, I’ve heard good things of the following ones.