Can a 2011 Ford Flex SEL power a 300W power brick for 40hrs without losing power?

Sorry if this is the wrong catagory, this is a part automobile and part PC question. Me and my family are taking a vacation from central Indianapolis to Florida later this year. We have a 2011 Ford Flex SEL. I am considering getting a Sager NP9370, which has a 300w power brick. The trip should be about 20 hours one way. Could I power this on the trip using the outlet, which pulls from the car battery? The last thing I want is to be stranded in Georgia because my laptop is such a power hog and it drained the power. 

you'll need to have the car on to charge the battery, I'd get one of those solar charger things such as this|10409928&CPNG=Home+Improvement&kpid=10409928&LID=PA&ci_src=17588969&ci_sku=10409928


it'll slow down the drain while you play and if you happend to drain it all the way simply stop chaging the laptop and let the car charge for a bit, there might be more powerful ones, if you had enough dough to get that laptop I'm sure a solar charger shouldn't be too far out of reach you

remember to turn off wifi and blu-tooth, lower brightness

and replacing the two mechanicle HDDs with SSDs will help with power consumption

if you can swap out the ODD with a Battery pack that will help too

300W * 20h = 6kWh, battery (typical car battery, your may of course differ) 12V * 40Ah = 0.48kWh - so no and far from it. But then you have to consider the charging power when engine is running - maybe there are some specs in the manual.

I'd trust this guy, sounds like he knows how magnets work


Car battery: minimum 45 Ah for such a car @ 12 V (about average voltage of car battery, anywhere between 11 V and 16 V usually) means 45 A . 12 V = about 540 W per hour can be discharged.

Average car alternator for small family car like a Ford Focus (don't know the Ford Flex, we don't have it in Germany): 100 to 130 A, let's say somewhere inbetween @ 13.8 V = about 1500 W of electrical energy produced per hour the engine is on. While the engine is on, devices are run from the alternator first, battery second.

There is a in/conversion loss, let's say it's really bad and there is 40 % loss inverting from 13.8 V DC to 220 V AC and converting down to 19 V DC again, and the AC output of the converter is 300 W @ 12 V, that would mean 300*1.40=420 W is needed to produce 300 W of output power. So even if the airco, power steering, radio, satnav, CB, lights, seat heating, etc... would constantly take 1080 W (everything on at the same time could amount to about that), and the laptop would drain 300W constantly, the laptop would still not drain any battery charge. The laptop however only uses about 140 W of electrical energy maximum as per spec of the AC/DC converter, so there will be no battery charge consumed whatsoever and it's perfectly safe to use the laptop while the car engine is turning.

Now let's say the alternator breaks, how far would the car battery bring you? 45 Ah was the spec of the battery, that means the battery can discharge 45 A in one hour maximum. So what does that mean, that means that there is 45 A . 12 V = 540 W of electrical energy that can be discharged by the battery per hour. The laptop is rated at 140 W @ 220 V (AC) = 0.64 A. Again, that is drawn from the inverter, and let's say there is a terrible 40 % inversion loss, that would mean 0.64 * 1.40 = 0.9 A of current is drawn from the car electrical system to produce enough power for the laptop at full load. The battery can deliver 45 A per hour, or can deliver 0.9 A over a period of 50 hours, because that's the same amount of electrical energy. So without any charge from the alternator, with only a fully charged 45 Ah car battery, the laptop would be able to run for about 50 hours at full load. But as I said, the alternator will take care of the elctrical power needed to use the laptop, the battery is out of the equation because the engine will be turning.

Now someone that knows that type of car, please look up how many kW of power the engine has, how much fuel it consumes, then knowing the performance of the alternator, how much fuel will be consumed just to produce the electrical energy for the laptop?

Oh and I know it's 110 V in the US but I took EU values because then I could read the wattage of the power brick of one of my laptops to make sure. At 110 V, the wattage will be twice as high as at 220 V, so I expect a power brick in the US to say 280 to 300 W at 110 V maybe? Here that would be 140-150 W at 220 V, and by now we're at about 240 V to be exact.