@saladin Jason, I just had my very first BetterBatt battery fail on me. One of my BLN-1 batteries that I've had for at least 7 years. Probably hasn't been used all that much, but it's brother and sister are still going strong!
No warning of any kind. Put it into the OEM charger, and it immediately threw an error. Same in the aftermarket charger. Dead as a dodo. Had worked perfectly up until then. Removed from camera. Put in charger. Died.