You need to read up on chins some more:
and look at what hey are doing now:
I think ever since Will BBQ'd the chins, its been on a downward spiral...
redodo and ampere time seem to be better for budget, but they may just be made by the same ppl...
I've seen these videos. Sure, Chins has knock-off cells. So does Rododo and Amper Time (now Li Time) and nearly every other brand. There are only half a dozen OEMs. These cells are all coming from the same few places. No one is rigorously auditing any of them to confirm whether/how often they're mixing in b-grade/refurbished, so you can pretty well bet they're all doing all of the above to save a buck. For the right price, I buy anyway, knowing it's always a roll of the dice.
RE: bus bars and gauge sizes and BMSes and heat sink sizes, first of all, the BMS size is prominently advertised on all of the good bargain buys, which I appreciate. If it's too small for your application, that's on you as the buyer to buy the correct product IMO.
There's two sides to the coin on beefy components. Bigger is not always better. It's obviously always safer, but obviously more expensive too. So there's a sweet spot, and we can disagree on whether a given brand nailed the sweet spot. But it's easy to measure whether they FAILED to be in the ballpark. Unless someone can show me heat cam evidence of Chins or Li Time or any other bargain battery failing under its specified load limit due to small internal wires or bus bars or heat sink, I don't care that much whether their components are less beefy than the competitor that costs 2-3X as much. Unnecessarily beefy components are not worth the difference. Big enough is big enough IMO. When I look for quality on the internals, I'm looking for whether there's evidence of cheap DIY hacking (like manual-labor soldering for example), which there IS in many cases. But not with Chins and not with Li Time. Those are quality bargain buys IMO. I'm totally fine with packing tape. I challenge anyone to dislodge those cells without opening the case. They're secure.
RE: batteries failing upon arrival, Chins and others may not have warranties, but they do have limited return policies for faulty product. I have 4 Chins 100AH that work fine, but if any one of them showed up faulty, I'd send it back immediately and I'd understand that that's common with all LiFePO4 brands. The important part is whether the company honors its returns promptly. If anyone can tell me Chins does not honor returns, THAT would be a huge red flag and I would probably stop buying from them. But I haven't seen an instance of that yet.
RE: the Chins solid-state battery, that was a prototype. To my knowledge, they don't sell that battery, probably because Will blasted it to hell in that video. I've looked for it. Search "Chins solid state battery" on Amazon. You won't find it. It was NMC, not LiFePO4. Will himself confirms LiFePO4 is safe in that video while he's nuking the NMC battery.
Now, to be fair, he did call them out for being vague about whether the cells were NMC in the first place, and if they continued practices like that... that would also be a red flag. I'd argue Will gave them a hell of a slap on the hand for that shady marketing. Hopefully, they got the message: chemistry must always be clearly labelled. But none of that has any bearing on the quality of their LiFePO4 products. When you type in "Chins battery" on Amazon, it's 100% LiFePO4 as far as I can see.
RE: capacity tests, I've capacity-tested all four of my Chins and they overdeliver up to 5%-ish. I just uploaded a video yesterday showing the 100AH giving me 105AH on a trolling motor bench test. Now, is it possible you get a dud from them that only gives 90AH. Sure. Send it back. I would. And if they won't replace, that's when I don't buy from them anymore.