My dell inspiron 6400 battery is not charging. The

Hello there:
what you can try to do is to remove the battery and unplug the power cord from the computer
now inspect the connections on the battery and the computer and clean both of them with a q tip and some rubbing alcohol make sure that it is really clean and let dry
now press the power button and hold for 30 seconds
now insert the battery and the power cord and start up the computer and see if this helps if not i would have the battery tested to see if there is a dead cell if so you will need a get a new battery. ok
hope that this is very helpful
best regards michael