Guys, there's no screening or cherry picking going on. Most cells are made in China by a number of different companies. Enerland is the only company I know of that makes the cells and also sells completed packs, as Polyquest packs, but I'm sure there are others that do the same.

Either way way here's how the packs you buy from the lhs, tower, Hobbyking etc are made. Someone who wants to sell packs gets in touch with a lipo company in China. The lipo company says we have cells in these capacities and in grades A, B and C. The cells are given these grades based on a few rudimentary tests after being manufactured based on internal resistance, low load charging and discharging performance etc. You need to remember these are quick, low load tests not full blown high load cell matching like in the NiMh days when paying extra for that Trinity pack with matched Panasonic cells was well worth the extra dough. Only a small sample of lipo cells from each batch get more extensive and higher load testing that would even come close to what you could call matching, screening or cherry picking. So even picking grade A isn't that much of a guarantee. Maybe the factory has a AAA grade option where they test a greater number of cells per batch to try and ensure a more accurate sample but it's still not a guarantee. Either way more times than not one factory's cells are in more than one company's packs. Even Enerland's cells end up in packs other than their own Polyquest brand.

So the guy who wants to sell packs picks a factory, then picks the grade. Now they can have them shipped to the US for assembly and sticker slapping here. Or they can have them assembled by the same factory there, maybe another factory there and have them shipped wherever with stickers already slapped on.

I honestly hate lipo conversations though. The whole industry is a sham, especially when it comes to C ratings. There isn't a lipo pack out there that can discharge anywhere close to its discharge rating without sustaining damage. BigSquid had a video years ago of a 3s pack being discharged by a pair of automotive battery testers which made for an amp draw (I forget exact number) right at the packs constant, not burst C rating. Either way the pack's voltage dropped from 12.6v (fully charged) to about 9v instantly when the test started which would've triggered the lipo cutoff in the esc. How can you give a pack a constant c rating that would trigger the cutoff when you try and draw a load equal to the constant c rating? Oh and btw they let the test continue and the pack was on fire in about 3 minutes. This was 5-7 years ago and things have only got progressively worse with inflated c ratings. I can't find that big squid video anymore but there are others on youtube showing the same thing with these inflated c ratings. I forget whether it was SMC or SPC but one of them actually wrote a letter on Facebook calling out other manufacturers for inflating ratings because they get their cells from the same place as other sticker slappers and they had to inflate their own ratings to keep up.

Go ahead and think you're getting better because your company charges more and/or says they do more. The reality is the equipment to test and prove that you're really getting more costs more than their annual advertising budget. And if they had that equipment they'd be posting discharge graphs from it (and not the Eagletree stuff they used to post back in the day) to prove what their packs are truly capable of. No company will do that because it would disprove their own ratings (if you're a current customer would you want to see how much they've been lying to you?) and it would make them look bad compared to the competition's inflated ratings. Well at least to the morons who don't like concrete data and would rather believe cheap marketing hype than the expensive testing equipment. So I'm pretty confident none of the companies selling packs would actually buy that equipment and if they do have feel free to tell us the make and model. The factory that makes the cells usually (not always) does have that equipment, but like I said only a small sample from each huge batch get more extensive testing on equipment like this. And the factory may not even take the time to test a sample from every batch and instead just down grade the batch to B or C rating.

One of these days I'm going to win lotto and I'm going to buy the equipment necessary. Then I'm going to shame the entire lipo pack industry with real numbers on a website and post it on all the forums. Until then I hope someone starts regulating the industry with a realistic c rating system, one that keeps the cells above the cutoff voltage and preferably doesn't cause fires in 3-4 minutes. End rant.