Car Power Inverter + Macbook Pro

Hi everyone. I'm going on a trip soon so I am looking for a reliable car power inverter for my 2007 Macbook Pro. My car has 2 power outlets (12V / 120W). I know there is a 15A fuse, so the maximum it can handle is 180W, but of course I do not want to take that risk and stay around the recommended 120W. Because of this, it limits the number of choices I have concerning power inverters. I have seen one from Duracell called the Pocket Inverter 100. Here are the specifications:

AC Output Power (Max Continuous): 80W
AC Output Power (Peak): 100W
AC Output Surge Capacity (Peak): 160W
AC Output Voltage (Nominal): 120V
AC Output Waveform: Modified Sine Wave

So, this leads to a few questions:

(1) The MBP Magsafe Adapter requires 85W. However, this inverter can provide only 80W of maximum continuous power. Will this be sufficient to charge and run the MBP in the car?

(2) I searched around and read a few posts by others regarding pure sine wave and how it is important to have it running to laptops. Now, this inverter has an output of a Modified Sine Wave. Will this be fine and will the Magsafe adapter be able to handle this?

(3) Do you guys have any recommendations for car power inverters within these specifications?

Thanks for your help!

 

1: Yes

2: dont matter as your ac/dc charger will turn the Modified sine back to DC and filter it anyway. Pure sine is important on SOME AC powered devices and low grade adaptors

3: your Car will handle pretty much any power inverter up to 400 watts rated AC output. so go find something rated 200 - 400 watts from any automotive shop, Walmart or electronics supply.

 

Oh, I should have mentioned that the power inverter will be plugged into the 12V power outlet inside the car. With a 15A fuse, the maximum output the outlet can supply is 180W. There's no way 200W+ will work, correct?

 

incorrect, I use a 400 watt unit on a 15 amp fuse all the time, the inversion circuitry nullifies the watt conversion for inverters up to a certain point, ft it comes with a 12 volt outlet adaptor with the unit you are pretty much safe due to UL / CSA regulations. I believe anything over 500W should be hard wired to your fuse panel but my reference material is not handy.

 

Well, that will definitely be better if that is the case. Why does both power outlets in my car have 12V / 120W labeled on them then? I assume that's the maximum recommended power output. Also, can you explain your rational above?

 

in a DC to AC inversion circuit a boost circuit is used to draw a lower volatage lower amperage power and boost the output by use of transistors etc, as long as your INPUT side is rated lower than 120W your output wattage has absolutly no bearing. My 400 watt inverter's input side is 10.6 - 16V DC 85Watt rated but has an output of 115AC 400 watt continuous and 500 Surge. I looked at my 2000 Watt inverter and its input side is 12V 350Watt

Ok I just looked it up and most of the consumer grade units dont use much of a boost circuit but will still power in the 300-400 watt output range but you will be limited to approxamatly 200 watts (14V * 15 = 210 automotive voltages say 12 V but are actually 13.8V when charged and when running slightly over 14)of Continious use ( 4 hrs or more ) before you may damage your fuse. Sorry for any confusion I may have caused, as the inverters I use are primarily industrial and hard wired.

 

No problem, crazycanuk. So in other words, for consumer grade power inverters (like the ones I will be purchasing), the power outlet output and input does not work the same way you presented above?

I should only purchase a power inverter will a continuous power output of 120W or less?

 

I would go with a 200-300 watt unit and you would still be safe but if you find a cheap 120-150 that should more than suffice as a inverter only pulls the power it NEEDS to create the amperage your devices require. if your unit needs 80W the inverter will only create 80W of power, no matter how cheap of a unit it is.

 

Well, let's say I want to purchase an inverter to power 2 Macbook Pro's (each rated at 85W), thus making the total power output necessary from the inverter to 170W. If I get a 200W inverter and it has a continuous output of 160W, this will only supply 80W to each laptop. Now, 160W is far greater than the recommended the 120W on the power outlet. Won't this cause problems?

 

shouldnt as my wife has a walmart special in her van that runs 2 toughbooks and a DVD player, with a total of 245 watts off her power port with a 15 amp fuse. all I can say is give it a go

 

Haha, it's all fun until a fuse is blown and I'm wondering why half of the electronics in car has stopped working.

What does watt rating on her power outlet say though?

 

says 120, in a 06 Dodge caravan, and shes been using that setup for 2 years.

 

Well, in that case, I guess I'll give it a shot before the trip and hope everything goes alright after that. Thanks for your help.

 

NP, have a good trip