Some actual figures may help. These are for full brightness, average figures @ 12.5v with the computer
battery not receiving any charge. These are with a DC to DC converter. Using an
inverter the
consumption is about 30% higher.
IBM T60P (15 inch laptop) 2.9A
MSI netbook 1.0A
I have not carefully checked the iPad2 that I have, but about 0.6A is close (wifi on but no gps)