@meeper pretty sure its an old notice. batteries generally aren't removable and they do tend to be a bit smarter these days. (thinkpads do charge cap, steam deck supports it though valve has it speculate when to full charge or not.)

then you get LiFePo batteries that *like* being charged to 100%, though those aren't being put in mobile things.

if it were up to me we'd be using manganese-dioxide nanowire batteries, as in lab tests those just... don't wear out.