Danger using > 45-watt power adapter on MacBook Air?

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Danger using > 45-watt power adapter on MacBook Air?

Is there any potential danger connecting my my late-2010 MacBook air to a greater-than 45-watt Magsafe power adapter? eg, could the battery get charged more quickly then it's expecting and therefore possibly shorten its life (as can happen with some battery technologies)? http://en.wikipedia.org/wiki/MagSafe reads: "Though the 60 W MacBook and 85 W MacBook Pro MagSafe connectors are identical, Apple recommends using only the adapter provided with the machine."

If there is no danger, and the 45, 60, and 85 watt MagSafe adapters are all the same physical size, then why not always by the larger adapter (and therefore be more-potentially compatible with any other MacBook I might use/own in the future)?

To note: a representative at an Apple Store told me it was fine to hook up my brand-new MacBook Air to adapter they had at one of the "workstation" tables in the store. Now I'm regretting that. If said adapter is a higher-power one (working to find that out), then am concerned my new MBA might have experienced unnecessary "battery wear."

Maybe there's a FAQ that addresses this topic?

MacBook Air

Posted on Apr 17, 2011 8:25 AM

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Answer 1

Apr 17, 2011 8:29 AM in response to hydrostarr

You can use a higher voltage charger, but not a lower one:

2. Select the appropriate power adapter for your Apple portable computer. You can use a higher wattage power adapter, but you cannot use one with less wattage without potential operating issues.

From http://support.apple.com/kb/ts1713

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Answer 2

hydrostarr Author

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Apr 17, 2011 8:45 AM in response to applefandan

Great, thanks for quick followup. fwiw, also found: this ifixit reference which points to this support article:

http://support.apple.com/kb/HT2346

which quotes:

"

Power adapters for Intel-based Apple portables are available in 45W, 60W, and 85W varieties. Although you should always use the proper wattage adapter for your Apple portable, you can use an adapter of a higher wattage without issue.

For instance If you have a MacBook (13-inch Late 2009) that normally uses a 60W adapter, you can also use an 85W adapter with that computer. You would not use a 45W adapter with that computer; it would not provide enough power for that MacBook. Using an adapter of higher wattage than the adapter that came with the computer will not cause the computer to charge more quickly or otherwise operate any differently than using the adapter that came with the computer.

"

Also, additionally: any similar problems with T-style power connectors vs L-style connectors?

http://support.apple.com/kb/ts1713

The question remains: why not always just buy an 85-watt power adapter, for maximum flexibility amongst all potential MacBook gear I might own one day? (An apple rep said they were all same physical dimensions... unless there's different weight?) Don't see any downside, even when concerned about overall power draw of the system... which might be a problem when hooking up to my car battery (for instance) at which point I would want to keep the power-draw lower...or something like that.

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Answer 3

Apr 17, 2011 12:26 PM in response to hydrostarr

The larger supplies are bigger physically and heavier but they are all the same retail price. If you aren't buying it to carry around with you then buying the 85W will give you the most flexibility.

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Answer 4

hydrostarr Author

Level 1

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Apr 17, 2011 3:30 PM in response to Brian Caslis

Excellent, very helpful, thanks.

How about the old T-style (vs. L-style) connectors and their associated power adapters. (We have several of those in our office--a big Mac shop.) Will those work just as fine for my MacBook Air without any problem/damage/danger?

more info on about the T- and L-style connectors: http://support.apple.com/kb/ts1713

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Answer 5

w7ox

Level 4

2,407 points

Apr 17, 2011 4:05 PM in response to hydrostarr

No.

Phil

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Answer 6

Apr 17, 2011 4:42 PM in response to hydrostarr

Yes it's fine and I've done it. I posted this in another thread also:

http://support.apple.com/kb/HT2346

"Power adapters for Intel-based Apple portables are available in 45W, 60W, and 85W varieties. Although you should always use the proper wattage adapter for your Apple portable, you can use an adapter of a higher wattage without issue.

For instance If you have a MacBook (13-inch Late 2009) that normally uses a 60W adapter, you can also use an 85W adapter with that computer. You would not use a 45W adapter with that computer; it would not provide enough power for that MacBook. Using an adapter of higher wattage than the adapter that came with the computer will not cause the computer to charge more quickly or otherwise operate any differently than using the adapter that came with the computer."

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Answer 7

hawleyrw

Level 3

629 points

Apr 17, 2011 4:48 PM in response to Brian Caslis

I've been using my old 60W "T" adapter with my MBA 13 ever since I got it. Works great.

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