I have fitted a new, not Dell, main battery to this laptop. It says plugged in not charging. I have pressed F2 then loaded default setup but the battery still does not charge. I have run the Dell main diagnostic tests and it then suggested two downloads which both flashed the bios bring it up to date. When I go into setup it shows that it does not recognise the power supply which is the one it came with when bought from Dell. I am unable to scroll down to this entry but doubt I could change it even if I could. Does anyone know how to get this laptop to charge the battery?