93 Concorde Int Lights flashing when on Battery Charger

My wife has a 93 Concorde. She started it up yesterday morning and then it died. When she tried to start it again, there was NO ELECTRICITY AT ALL. No Interion lights or guages or anything. The battery appears to be totally dead, so I put he charger on it. Then the interior lights FLASH (as if some relay is kicking off as soon as the charger applies some charge). That is a wild guess. Does anyone have a better guess or any suggestions as to what to look for?

Thanks