laptop not charging?

I have purchased a new battery and a new charger and my laptop still says it's not charging. It is a Dell Inspiron 1525 bought in July of 2008. I have cleared everything off the computer and went back to factory settings. I reinstalled Windows Vista and all the drivers again. It is still not working. I took it to a guy at Staples and he said 98% of the time it is either the battery or the charger. I don't want to pay $50 for a phone call to Dell!! Do I need to do something with the BIOS again?