DC Adapter for Macbook

[zboss]

I just recently picked up a DC adapter for my macbook air... its great! I save at least an amp/hr when the battery is already full vs. charging when I probably save 2 amps/hr. This is important because I work from the boat and I'm probably running at least one PC for 16 hours a day.

Several companies make them but this is the one I got...

Macbook 12V 12VDC Adapter Charger with MagSafe Connector

I went to the apple store and bought the old style to new style magsafe adapter and it works perfectly.

[Wotname]

Thanks, good info

[CarinaPDX]

Thanks for the info. It looks interesting, but since it tops out at 60W won't work for the largest MacBook Pros.

I just had to order a "new" power supply for my late 2006 MacBook Pro (17"). The connector on my existing one is failing, as they are prone to do. The experience was a bit of a nightmare. It turns out that Apple doesn't sell power supplies that work with the early Intel MacBooks. When Apple came out with the MagSafe 2 connector they changed some of the info encoded in the connector, which required a firmware update to the computer's SMC so it would recognize the new connectors. Only Apple in their infinite wisdom didn't offer SMC firmware updates for the early Intel products, and of course they discontinued the old power supplies. Fortunately clone ones can be had on eBay for about $20, but it is necessary to check that they cloned the older power supplies and not the current ones. What a mess. At least I should have a functioning one next week...

Greg

[CarCode]

I have tried two DC power adapter for my 2009 MacBook 17". Both came with the magsafe 1 and sufficient watts. But both disturbed my EyeTV Netstream Sat device. It only works with AC power adapter attached to the MacBook. So I guess the DC power adapters makes some noisense.
After all I can use the EyeTV only in the harbour. So it doesn't matter.

Gerhard

[colemj]

I went into an Apple store, asked if they had an old broken MBP charger (they did, and gave it to me for free), cut off the cord and wired it to a $10 multivoltage car adapter.

This was before anyone had a DC power adapter for the Macbooks (even Apple). The above costs a little more, but is worth the ease.

I believe the MBP will run off the 60W supply, but not charge while running. It will charge more slowly when not in use.

Mark

[CarinaPDX]

According to Apple the various MacBooks won't run with smaller power supplies than was originally shipped. So a 60W shouldn't work with my 17" which came with an 85W supply. The power supply bricks send DC over 2 wires to the MagSafe connector - nothing fancy there. But inside the connector there is programming that identifies the wattage (among other things) to the computer's SMC, which makes the decision to use that supply or not. That is the purpose of the small 5th pin in the middle of the connector: it is a serial interface (also used to turn on the MagSafe's LED). I have no idea where the cloners are sourcing their connectors; in the early years Apple refused to sell or license them to anyone, which had a few long-term Apple partners more than a little upset. Perhaps the patents have expired - I just don't know. But the difference between the computer accepting the supply or not is inside the MagSafe connector, not the power brick. And the current 85W MagSafe will not work with my MBP because Apple didn't offer an update so my SMC will be happy with the new info in the connector.

Mark, you are very lucky to get the cord. It seems most of the MagSafe era power supplies fail because of either a frayed cord near the brick or problems in the connector, not so much a problem with the power itself. It is the connector that is unique and valuable - there is no shortage of 18V DC power supplies.

Greg

[zboss]

Yep, we had two power supply connectors go bad at the computer end. We also had a lighting connector go bad at the USB end.

BTW.. mcmaster carr carries two ultra heat shrink tubing sizes that might fit over the ends and shrink down small enough to stiffen the wire:

http://www.mcmaster.com/#7831K11

and

http://www.mcmaster.com/#6855K14