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Quasi-Sine Wave/Apple MacBook

I have a Quasi-Sine Wave Inverter on board. Having recently bought an Apple MacBook, I would like some advice:
1. Can I run the MacBook via the Inverter supply.
2. If not - can I fully charge the MacBook battery without damaging it?
3. Is it possible to run a MacBook directly of the 12 volt supply (possibly using some kind of adaplor)?
Any advise would be appreciated.
Mike Brown

Asked by: Mike Brown  | 12.29pm, Monday 15 March

WW says:

Apple laptop power supplies are pretty tolerant, but people have certainly reported problems with a quasi-sinewave inverter. I would personally be reluctant to run a MacBook off one - it doesn't take much to fry a laptop battery! You can buy a 12v pure-sine inverter for as little as £150 (Sterling's 200W model), which is a worthwhile investment to safeguard your £800+ laptop.
Alternatively, yes, you can buy a 12v adaptor. These aren't cheap: Apple has an exclusive patent on the 'MagSafe' power connector, which makes it difficult for third parties to produce adaptors.
Nonetheless, they do exist. Some are available from the US only so be prepared to pay for international shipping. A few links: http://quickertek.com/ , http://mikegyver.com/Store/index.html , http://www.hypershop.com/HyperMac-Pure-DC-Car-Charger-for-MacBook-p/mbp-car.htm . You might find some more interesting information at www.macsailing.net .

Richard Fairhurst  | 2.39PM, Monday 15 March

WW says:

Generally, most laptops work very well on quasi-sine wave inverters (even the really cheap "square wave" sometimes) as the powerpack is designed to cope with a wide variety of input voltages, frequencies and stabilities of the supply. All of my laptops have cheerfully charged, and run, from all 230V supplies aboard various boats over the years.
However, for the definative answer, I am sure that Richard Fairhurst, the editor, and an avid Mac enthusiast, will give his view!

Mark Langley  | 12.52PM, Monday 15 March

Only one issue that springs to mind... if the ASUS netbook normally takes the 12V power through an adaptor, then it will be regulated to 12V.
Most DC power supplies on boats are not regulated- a battery will produce anything from 10.5V to 12.8V. With the engine running, this could easily rise to 13.8V or higher.
Be warned that such use will probably invalidate the warranty of the computer- it may suffer damage from the variable input voltage.
Might be worth double checking on the tolerances that the machine can handle- and that it is surge protected (the transformer usually deals with this, preventing voltage or current spikes from damaging the system).
Not to put you off, just something to check.

Mark Langley  | 10.13PM, Monday 29 March

Readers say:

Hi if you have the money go for an ASUS net book as they run on 12v not all check the back of the computer and the connect direct to 12v supply minus laptop battery.Cost at present is around £200 from curries.This way you can leave the computer on board and have no problems in charging the computer battery.The only thing to do is also get an input lead for the supply or cut the mains charger cable and attach it to a cigaret plug in . Note it must have the correct input conection + and -

r martin  | 1.42PM, Saturday 27 March

An interesting alternative - out of interest, do you use a dial up dongle for internet access and if so can you recommend any particular one for reliability and good value?

Mike Brown  | 9.02PM, Saturday 27 March

Hi Mike i am using a t-mobile dongle on contract which costs £15 per month. I have had no problems with it over the last 2years. Don't use it overseas ie France , Spain etc due to cost.Aldi in Germany sells a dongle which is not locked for euro 38 and in spain for euro 80 this is from an internet shop. The advantage with this is that you can put a pay as you go in the dongle from the country you are in and it is cheap to surf.Also with ref to the net books when you have modified the input lead you can also plug in to a car cigarette socket and use in the same way. Asus has a few models at 12 volt the eepc 7inch with microsoft xp or the 10inch with xp or widows7. Hope that this helps.

r martin  | 9.09PM, Sunday 28 March

Very helpful, thank you

Mike Brown  | 12.03AM, Monday 29 March

Thanks for that, Mark.
I will proceed with caution!

Mike Brown  | 12.21AM, Tuesday 30 March

Hi Mike back to you after reading Marks note I have had no problems I also run my lcd tv direct without the mains transformer as this is also 12v. With the tv when the voltage drops so does the reception. With the computer the 12v boat battery is the same as the power pack on the computer as the voltage drops the battery sign comes on to tell you to switch to mains power.The out put from the mains transformer is .2-4 above 12v as I have measured it. Alternatively you could use an inverter to convert the 12v to 230v then to 12v to input your computer. Hope this has helped you. The 12v tv has functioned for over a year with no problems so has the computer. What mark says with the voltage from the engine running is higher is correct but I dont use the computer or tv when I am cruising. I have a 240v gen separate to provide me with mains power also on the boat. I also run all my lights which are led 12v direct from the battery these were also supplied to run from a transformer from the mains also with no problem. Hope this helps.

r martin  | 9.06PM, Tuesday 30 March

Thanks again,

Mike Brown  | 9.23PM, Tuesday 30 March

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