Battery not detected

Hi.

I've been using this Dell Vostro 1700 for an year. Now I face a problem with the battery. For the last couple of days I've been warned that the battery is reaching the end of life although it is charging normally. Now I see a wierd message in the system tray. I see a battery charging icon with a cross mark on it saying "No battery is detected".  If I remove the power cord, the laptop does not shutdown. It continues to use battery power. So I see that the battery is being used, though it is not being detected!

I've seen a couple of people discussing on the same problem, but I couldnt figure out any specific solution. Did any of you figure out the root cause or a solution to this?

Thank you!