Then you might as well just buy a car charging cord for the Macbook that directly plugs into the 12V outlet.Well, I bought the inverter. Funny thing is we are converting 12 Vdc at the power port up to 110 VAC and the plugging in an apple charger that drops that down to about 8 VDC to charge the Li-ion Mac battery. I wonder how much is lost in all that (and if a serious hacker could create something that takes a direct DC to DC path and is more efficient)?
Apple A1172 A1175 charger your MacBook in the car 85w MagSafe 1 AC Adapter Power Supply