My Dell Laptop Latitude D600 refused to charge. I have try another adaptor plugged in with it but it was not charging and it doesn't power without the battery either. Could it be the charging port or because I've used up the battery juice. Is there a way to charge the battery without inserting it in the laptop. Someone should Please help me with useful information.

If the laptop power on using adapter without the battery in it, it means the battery has reached its last bus-stop. Go and get another battery