So, I have a 233/512 running 9.2.2 PB and now get the Red X on my battery. Just how did I get this honor?

I was trying a USB card that has worked in the past and I tried it the other night and the computer froze. I pulled the card out and restarted and got the unhappy mac sign, the ? blinking in the disk. I dont have the back up CD's so after numerous restarts, tyring every way I know, I got it working to normal order. Except now, battery is not recognized. I have tried putting it in the left and right bay, tried the apple battery reset 2.0, restarting holding the shift, restaring holding the P and R keys, and nothing. The battery was fully charged, about a week old and was working just fine. So is it the hardware that needs replacing, the battery or what? How did it suddenly just go from working fine to nothing. Thanks.