[MrForbes]

If you want help figuring out what went wrong, you might need to provide some clues. Like, what was done to the battery? was it just sitting in a nice dark cool room all by itself? was it connected to a charger? was it exposed to temperature extremes? was it shorted out? How old is it?

As mentioned, it doesn't really matter for this battery, but if you have others that might be mistreated some how, it would be helpful for you to tell us all that you know about what was done to the suspect battery.