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MBAddict

macrumors newbie
Original poster
Sep 7, 2011
4
0
Does anyone have anything they personally use already to achieve this? I take road trips often and was looking for something before my Air arrives. I check the forums and google but just found out the airport charger(?) doesn't charge it and a bunch of links to no reviews or 1 review items on amazon that look outdated. This is the new 13" Air by the way.
 

MrCheeto

macrumors 68040
Nov 2, 2008
3,508
343
I personally use a power inverter.

I got mine at Walmart for $40 and it supplies more than 200w, which is more than I'd ever need. Considering the MacBook Air uses 45w, you could definitely find one with that much power for less.

It's great because I can use it to charge anything, including my iPhone via USB.

Modified-Sine-Wave-75W.jpg
 

macbookpro45

macrumors 6502
Jun 20, 2010
342
0
I agree the power inverter is the best option because it is more versatile. Just make sure you turn off the power inverter BEFORE turning off your car. A few years back I forgot to do that and my car battery was dead when I tried to turn it on a few hours later. Although nowadays most newer cars probably have systems that do not let you use the lighter ports unless the car is on.
 

alecgold

macrumors 65816
Oct 11, 2007
1,344
843
NLD
Power converters are very inefficient. Certainly the cheap ones. The need to go from 14v dc to 110/220v ac and then it needs to get back to the 18v dc.
The hypermac car charger I have just ups the voltage from 14v to 18v.
I have no idea how well available they are, but it's pretty good in use and economical (less fuell Consumption, less heath being produced) its just not as versatile as a 220 converter.
 

MrCheeto

macrumors 68040
Nov 2, 2008
3,508
343
I leave my inverter plugged in 24/7 charging my bluetooth headset.

I have a diesel...two 12v batteries. Not sure if that makes a difference, but I've left it sitting for five days with zero problems.
 

flynz4

macrumors 68040
Aug 9, 2009
3,244
127
Portland, OR
I personally use a power inverter.

I got mine at Walmart for $40 and it supplies more than 200w, which is more than I'd ever need. Considering the MacBook Air uses 45w, you could definitely find one with that much power for less.

It's great because I can use it to charge anything, including my iPhone via USB.

Image

45W is actually the output power of the MBA charger. You need to have enough power for the input power the charger requires. The specs are 100-240V 1A. That is higher than 45W... but still within the wattage spec of your 200W inverter.

The picture in your post shows a 75W inverter. That would not necessarily be enough to power the MBA charger.. It's been a while since I studied power... but assuming your inverter produces a sine wave, then RMS power would be 120*1/sqrt(2). However, if it is a triangular wave, then I think the RMS factor would be sort(3)... and if it was a square wave... then it would be Root (1)... or 120 watts. It's been 30 years for me... so I might be rusty.

/Jim
 
Last edited:

VMMan

macrumors 6502a
Mar 29, 2009
766
239
If I were to get an inverter for the car, I would probably spend the extra $200 for a pure sine wave inverter.
 

MrCheeto

macrumors 68040
Nov 2, 2008
3,508
343
$200?

Mine cost about $40-50 and charges my 13" MacBook Pro with zero issues...

E'r'y day...
 

MrCheeto

macrumors 68040
Nov 2, 2008
3,508
343
What I'm saying is, why even bother when the $40 device has no apparent issues.
 
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