Some of them experienced noticeable capacity loss. Most didn't. Battery brand had a lot more to do with their longevity than any usage habits of mine.
Good to know, thanks. That I am using a Lenovo battery, and that they explicitly recommend not charging it fully to maximize longevity, and that failing to heed this suggestion (of which I was unaware) has led to unacceptable degradation -- with which they agree, and are replacing under warranty -- suggests to me that in this case I had better play along, except that it is not obvious how to do so under Linux. Maybe there is a huge longevity difference between even a 95% and a 100% typical charge, in some batteries? I wonder how much has to do with chemistry, and how much has to do with management as implemented in firmware? Oh well, I have yet to meet the complex piece of equipment that doesn't have quirks. On this laptop I have discovered that if I close the lid and then yank the power cable before the sleep sets in, it sometimes fails to sleep. So, I have learned to pull the power either before or some time after I close the lid. Manually managing battery charge is a bigger PITA, but not impossible. I would prefer to set what I want in software, obviously, but that isn't always possible.