There are a number of issues with what you’re saying.
You’re currently using cell datasheets as some kind of “Ah ha!” to counter the feedback from people in this discussion who have what is most likely, much more experience, expertise, and nuanced understanding of the topic. These include people who haven’t insulted you, and have explained in great detail the answers to the questions that could be gleamed from what you’ve been writing.
As a result of that, you’re very much misinterpreting what the numbers on datasheets mean.
To start, those datasheets aren’t written for you. They’re written for engineers to use as design guidance for devices with integrated battery packs, around which BMS systems are designed and also integrated. Those engineers span from electrical engineers, mechanical engineers, and integrations engineers who look at a system/product from different angles, and then coordinate their understandings to arrive at a final system.
This is also how BMS IC chips are treated. Those chips have their own spec sheets, with voltage cutoffs, temp ranges, etc. And they also have reference schematics that show examples of how to implement the chip into a circuit. What they DO NOT show, is the ancillary circuits needed to properly power the IC, protect it from the battery circuits itself, or tailor specific functions of the end device alongside what the IC is designed to do. This encompasses the assembly of the device (since factory or end user assembly has to be accounted for) and failure modes that the IC doesn’t accommodate.
That’s all to say, that you simply cannot point at a datasheet and go “SEE? I WAS RIGHT!”
When you do that, like you just did, you display ignorance and a lack of understanding of the topic, and so the conclusion that you’ve dug, incorrectly, from these sheets, doesn’t end up serving you or anyone else. And it’s also wrong.
You’ve ignore other lines in the sheet, like the fact that 2.0v is the BMS shutdown voltage.
That means that in devices using those cells, the BMS doesn’t just disallow charging and discharging, it has to completely shut down. Those barriers are separate and distinct from operational cutoffs. Shut down means the end user is completely barred from using the device, period. No charging, no turning it on.
The manufacturer is saying that if the battery hits that point, the device is to be deactivated.
There’s also this, as a qualifier of the data in the sheet:
“This Specification shall not apply to special applications requiring a high degree of quality and reliability where the failure or malfunction of the products may directly jeopardize life or cause threat of personal injury.”
Which makes your statement here:
^This statement, absolutely incorrect.
Look, you can do whatever you want with your own stuff. But this thread is a reference point for other people looking to learn about pack building. So the sweeping incorrect statements you’re making here about cell voltages, are not just wrong, but they’re irresponsible.
This isn’t helpful.
I point colleagues and DIY one wheel builders here for reference, and this whole shit show of a conversation could have absolutely been avoided if people didn’t use this thread as griefing/trolling entertainment.
Normally I don’t care, but this whole thing is now being dumped on my doorstep and I’d like to keep referring people to this thread.
I’m telling you to trust the people who literally work on these things professionally.
So as a professional, it is my professional opinion that you’re looking at this all wrong. And you’re doing so at your own peril.
Backtracking a bit.
There is a right and wrong. Degrees of risk don’t exist in a vacuum, and this is a publicly viewable forum that outsiders view for reference and guidance.
And so the angle at which you or anyone comes at a conversation about technics of a volatile and dangerous part of a dangerous hobby, matters. The good or bad faith from which an argument happens, matters. It all matters, and the context in which disagreements happen, also matter.
Personal risk ends where the publicly provided opinions and information begin.