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powering macbook air from 12v supply?

A friend wants to power her MacBook Air on her boat from a 12V source (DC) What should she do, to get the most power-efficient solution?

MacBook Pro, Mac OS X (10.7.4), MacBook Air

Posted on Sep 4, 2012 11:19 AM

Reply
11 replies

Dec 1, 2012 5:29 PM in response to John Reed6

Hey so John, all you need is a Dc-Dc converter. with 100 watts at 12 volts, you can step up to 16.5, with anything from 45- to a ways. It would need a magsafe 2 or magsafe 1 with an adapter, and would need a little soldering, but it's pretty easy. I could do it. My dad, (65) could do it. So all you need is the DC to step up, then you're good to go.

Sep 4, 2012 9:18 PM in response to SP Forsythe

I failed to mention that my friend has a very limited amount of available energy. She uses a solar array for power, which has a peak output of 100 watts. I'm afraid the combined inefficiencies of the inverter + the MacBook Air power adapter would yield less than 45 watts for charging the computer. It would seem like there should be a way of powerring directly from the 12V source, since the MBA takes 12V at its MagSafe terminals, I understand?

Sep 5, 2012 1:56 PM in response to John Reed6

By the way, I checked the MagSafe pinout configuration on Wikipedia. According to the reference, there are two instances each of 16.5V, and Ground. If true, this would sort of put the 12V system beyond a reasonable tolerance from the "required" 16.5V? It would be interesting to know how much tolerance the Air could stand on this voltage, and still charge and operate normally, without damage. Any clues, anyone?

Sep 5, 2012 7:08 PM in response to John Reed6

Looking at the system information power panel my MBA shows 8.322 volts on the battery. 12 volts would adequately charge the battery because the charging regulator is inside the MBA not the Adapter. I'm not sure how the DC is switched between the 4 connections as it is reversible as to how it connects with the MBA at its power port.

Nov 19, 2012 4:18 PM in response to John Reed6

Please. Please Apple explain to me why in your closed universe you justify the reasoning to not be compatible with simple, standard 12v adapters? I invest in 12v solar - not 15v obscurity. Individual energy production is the next Internet and we need simple solutions to adapt to energy options. I understand being a closed system and building proprietary systems but independent energy production is a fast evolving animal and Apple needs to see and embrace this trend. Open up your adapters and embrace 12v solutions. Trust me.


Embrace battery innovation and independent power generation and build user experiences to empower it. Your smart enough.

powering macbook air from 12v supply?

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