BAK released the new N21700CD 5300mah battery

The actual capacity is about 5400mah, and the power is slightly weaker than that of Samsung 50g and BAK CG

Do you have few samples in stock? I would add this cell to the ongoing cycle life tests for community.

Excellent news!

we have only 300pcs,The factory hasn’t mass produced yet

The BAK N21700CD will be added to my cycle life tests soon thanks to the vapcell Dennis support. :+1: And more to come! :wink:

@Padja cz, thank you a lot for the testing.

Anyway, I have to ask a question as I can’t seem to find any definite answer to this:

Is is true that even the latest Samsung 30Q revisions have unaceptably high self discharge?

I don’t have a definitive answer either. My tests only show the behavior of the cells under laboratory conditions, which can be interpreted as “showing what can be expected from the modern cell technology if everything goes well…” where everyone who has ever played with batteries has sooner or later come to the realization that this is not always the case.

So you probably have seen my other synthetic test Calendar ageing tests of mixed cylindrical cells - Endless Sphere where the Samsung 30Q6 passed without problems, the older 30Q146 pass it with similar results as well.

Yeah, I saw your post, which is why I wanted to ask :smiley:

Thank you.

You must be measuring voltage before you put them in the drawer and when you first take them out. Is there some reason that you don’t add this information to the data.

Because I didn’t find this parameter that interesting? :blush: (I find energy/capacity information more valuable) But this is a good question, I have the OCV data for “1 year” of storage and can add it to the table. Academic question is how set the conditions for proper reading OCV value of a “New” cell. I am adding 10 min rest time between each steps, but in this case it is not sufficient time for full relaxation.

I can’t make much sense of what is being presented in the “Calendar ageing tests of mixed cylindrical cells” thread. I’m not sure which line of data is related to a permanent, non-recoverable loss. What I’d find useful is knowing the resting voltage after a period of storage, meaning the self discharge over a period of time, and then the capacity after recharge, meaning the permanent loss due to storage time. Seems like it might require a few charge/discharge cycles to determine if the permanent loss is really permanent.

I think a 10 minute period after a load or a charge is removed will get really close to a final resting voltage. Most of the bounce is going to be done in the first 1 minute. Rough guess 95%. Close enough for government work.