It happens sometimes, in fact it happened to me 'cause I didn't know any better.
Apparently, I overcharged my lithium ion battery in my old IBM T40 Thinkpad by having plugged into the AC outlet for a prolonged period of time. That basically killed my battery; on a full charge I can use my Thinkpad for 5 minutes....WOHOOO!!!
Did you also overcharge as well?
Also, batteries can only be recharged for so many times before they fail. How old is your Tecra?