Hope everybody had a great holiday. Figured I’d jump in here and clarify some things.
One important thing I want to clarify is that I never said anyone else’s cells were definitely grade B. I just said that NPE was telling me grade A wasn’t available at the time, and my other contacts told me the same, so we didn’t have access to grade A. Maybe someone else had gotten a small amount through some unknown connection, something like that is always possible although it did seem unlikely. We feel very strongly that we always want to sell grade A (other than very rare cases where we explicitly call it out as lower grade), and they seemed to be coming in grade A soon, so we didn’t pursue getting any lower grade ones.
Now it does seem grade A is available in Taiwan and has been for at least a short period of time, in very limited quantities and at high prices. It will be some time before we have them (probably late February) just because it takes a long time to ship from Taiwan without spending insane amounts on shipping (and we don’t want to have to pass on that cost). So as always I can’t say what competitors are doing but it’s much more likely that others might have grade A now or soon, compared to when Cochise334ever talked to me before.
For the price complaints, you do have to keep in mind that P45B was originally developed for the supercar brands to make electric vehicles with - it is a “cost is no object” cell. It’s not intended to replace the P42A. So the P42A will continue to be much more widely used. But some customers like supercars and military and the like will want a cell like P45B that is substantially more expensive for only a small improvement in performance.
Still, our price will not be quite as high as what the current market is charging.
Anyway, onto the grade B questions. The article posted in this thread is a bit sensationalistic about the risks of grade B, but partially that’s because it’s talking about EVs. When you have more mismatched cells it is a much bigger problem in a large pack than it is for something like a flashlight with one or a couple cells. It also depends a lot on what exactly is meant by grade B as I’ll talk about more.
I don’t have concrete info on exactly what grade B is in each case. First of all grade B is not a standardized term. There are two categories of cells that might be referred to as grade B. 1st category is when it meets the public specification but not well enough to be used with their most demanding customers, who usually have their own requirements that exceed the standard specification. 2nd category is cells that don’t meet the published spec (these guys usually will have something like grade A1 and grade A2 or something to describe different levels of meeting the spec).
For the 1st category, it could be they are not matched as well to each other, or it could be that they have more self discharge than usual but still reasonable, or maybe capacity is less than the best possible. These are just examples of what it could be, it could be any performance parameter that comes out less than ideal. I have heard the self discharge one is a common reason for molicels to be rejected as lower grade but that’s just unverified info I heard and not official info - but that could be a potential guess here.
The second category is obviously the much scarier one. But even then it may just barely not meet something and not be a big deal when used in very small applications.
It’s always tough to tell with lower grade products, and only the company buying the cells can get details on why exactly they’re grade B. That’s part of why we don’t deal in this stuff.
Anyway, hope that helps clear things up slightly. Wish it was possible to clear up more.
. I got samples of P45B from Nkon this September (orderend in the spring) and lets consider them as B grade. In any case, they fulfills all catalog values in terms of nominal capacity, temperature below 80°C after finishing 10C continuous discharge and they really support 3C continuous charge rate. There is no problem even with 20C peak discharge and 10C peak charge rates. These samples are already running in my standard cycle life tests 5C discharge rate at 100% DoD and 1C discharge rate at 95% DoD, where they after 400 cycles perform very well (as expected).