Inspiron 9200 Battery

I have done a search for the above label, and found 60,000 posts.  I read page after page without finding an answer to my problem.  Please forgive me if the answer was in one of the 59,500 posts I didn't read.

My battery shows full via the lights on the back.  However, when I start up on battery, I immediately get a low battery-plug in message.  If I start on AC, and unplug when the system is up, I can work on battery power.  The on-screen battery meter shows full.

I suspect this is a battery recognition issue, and, based on what I read, may mean I have a bad board (but I am ignorant of such things).

Any help you can provide would be very appreciated.

TIA.

Mike