All li ion cells die someday.
I have some A123m1 cells recycled from 2006 Dewalt packs that are still going strong and might out live me.
Li ion cells get little shorts in them over time.
Enough of these little shorts will kill off the cell.
Quality name brand li ion cells are designed to die in a non fantastic way, not short out quickly when they die.
Cells designed to die in a non fantastic way are the only cells that should be used with a bms.
All rc lipo battery makers say to always charge rc lipo with chargers made for rc lipo batteries and to always attend the rc lipo batteries being charged.
Rc lipo can get large shorts inside the cell and cause the cell to die in a fantastic way.
A bms is designed to kill a pack if needed but the way they kill a pack was not designed for killing rc lipo cells that were not designed to die in a non fantastic way.
Rc lipo was designed for rc racing and max power, lowest weight.
Rc lipo was not designed to last very long or die in a non fantastic way.
Good for ebike racers that have money to burn I guess.