[moonlightsailor]

Please let us know how it works out.

[antipole]

I have just purchased a PWR+ 12V power adaptor for my Mac PowerBook, model AP4C. I ordered through Amazon UK and it cost me £24 including VAT & delivery.

It comprises the dreaded cigar lighter plug, a white box containing the works and a MagSafe-style connector. The MagSafe connector is clearly a Chinese copy that Apple has not yet stopped. It is elbow rather than straight, includes an orange/green indicator like the real thing, but the light stays on when disconnected from the MacBook.

It works just fine so far - only tested in my car, not at sea. When the MacBook is charged and asleep, the unit is scarcely warm to the touch, indicating the voltage step-up circuitry is efficient. When working hard to charge, the unit is only slightly warm.

I am very pleased with this modest-cost solution. I don't like buying a copy of Apple's patented plug, but as they have refused to license it or sell it to OEMs, this seems the only practical way around the problem so created.

[Philip_Fry]

Reading this thread, I'm somewhat mystified as to why when MacBooks are to be used when at sea, and therefore only 12 volts are available, people don't just use an inverter? This is what I do. Cannot see anything wrong in so doing.

My experience is that if the machine is powered in this way, rather than just on its own battery, then the screen is more viewable - very important when viewed in the strong daylight on a Motor-Boat.

[bobetter]

I would suspect that the reason is that most here are on sail boats and are interested in using as little power as possible. Using an inverter to convert DC from a battery to AC for a charger that then converts back to DC is less efficient than just staying DC.

Not sure what you mean by screen brightness, if the Mac is being powered externally from whatever source, full brightness is available.

[jagasail]

Besides more 'stuff' to manage, invertors are notoriously dirty with rf, interfereing with communications, particularly with ssb/hf/vhf radios. There are some clean invertors but you need to be careful. Most of those available at marine stores are quite noisy with rf.

Scot

[Philip_Fry]

Fair point as regards power supply's on a sailboat. This explains another question: > Not sure what you mean by screen brightness, if the Mac is being powered externally from whatever source, full brightness is available. < In my experience light in the saloon of a sail boat is not at all bright. Design I suppose. Very different indeed on a motor boat, windows all around. When just left on battery power, I could barely view the screen on my MacBook. Considerable improvement when powered by an inverter. And no, not the slightest problems with the VHF radio. Why obtain one from a marine supplier? I purchased mine from Maplins, a most reputable UK High Street electronic dealer.

[antipole]

Screen brightness can be set in the Energy SAver control panel. By default, the screen is dimmed slightly when on battery as a power-economy measure. If you want to keep the bright screen when on battery power, go to the Energey Saver control panel, select settings for battery and the Options tab and then unselect the 'Slightly dim the display using this power source'. Voila! But yes, your battery charge will not last so long.

And yes, my reasons for getting a DC charger were to avoid the inefficiencies of an inverter on a yacht, where I only rarely run the engine.

[adamlau]

I bought a dc to dc adapter (link: http://www.buymac.com.au/product/magsafe...r-macbooks) and have used it on the boat for the last week. It does a good job of charging the battery and maintaining power. I actually burnt out the AC adapter that came with my mac book pro when I ran it using the boats inverter. Have since found out that when the electrics were changed over from US to Australian the inverter that was put in was a modified sine wave. Live and learn...

[riddon]

I have just bought a 'Darktop' car charger for mac for about £20 off Amazon. Comes with magsafe adaptor. Just plugged it in and it seems to be working OK. Anyone had any experience with this charger?

Richard Iddon

[jennetheattis]

Hi

What have youre experience with the car adapter been? Is it still working ?
Any supplier you prefered

br
Janne