4 Replies Latest reply: Jan 8, 2013 10:55 AM by OGELTHORPE
BahamasTraveler Level 1 (0 points)

Have not used this forum before - thought the power supply would simply state the wattage but it does not (probably because it can accept a range of voltages). If a 75 watt inverter will power it, then I don't have to get one with cooling fans that are too noisy - not sure how I would even know if someone responds to this topic, so will include my email address. pfth@earthlink.net.  Thanks.      Peter

MacBook Pro
  • Kappy Level 10 (265,878 points)

    The AC adaptor for your model requires 85 watts, so a 75 watt inverter is not sufficient. Why do you require an inverter? Are you planning to power the computer in an automobile or a boat? An old rule of thumb is the inverter wattage should be about 1.57 times the wattage required by the connected equipment. That would require a 125 watt inverter, minimally; 135 watts nominally.

  • BahamasTraveler Level 1 (0 points)

    Want to use it on my boat - fans too noisy. Macbook Pro has a feeble electrical system as far as battery life goes and even when I shut it (sleep) it will kill the battery overnight. An inverter rated for 85 watts continuous should be ok though - they have peak ratings of 125 watts. Since it would be mostly maintaining a fully charged battery with the display normally blanked out (power saver) do you think that would be ok? Thanks for your quick reply - I did see 85 watts mentioned in other places in my searches.

  • Kappy Level 10 (265,878 points)

    Keep in mind that the purpose of the battery when the AC adaptor is connected is to provided additional power when the draw exceeds the capability of the AC adaptor. Of course this may be irrelevant if that isn't a likely event for your usage.

  • OGELTHORPE Level 8 (45,085 points)

    An Inverter may have a peak rating that will accommodate the power requirements for only a brief period of time, NOT continuously.  I highly recommend that you invest in a more robust inverter.