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View Full Version : 60W Power Adapter on MBA?



jho4evah
30th March 2010, 09:12 PM
Hey,

I have a MacBook Air, for which the charger has kicked the bucket... after only being 2 weeks old. Is it safe for me to use my 13" MBP's 60W power adapter on the MacBook Air?

Sebastianmonty
30th March 2010, 10:40 PM
It's an extra 15watts over so I would say no. I may be wrong but I know when I had modem trouble I used other power bricks with different currents and they all stopped working. All 3 of them.

koinonas
30th March 2010, 10:52 PM
If the MBA's only 2 weeks old and the Power Adapter has died, its probably worth giving AppleCare a call as they might be able cover it under warranty (unless it died due to external factors like having a cord ripped out or going for a swim).

My basic understanding is that Power Adapters will only supply power at the rate that the computer draws from them, up until their maximum rating. I've often used a 15" MBP (I think 85 watt) adapter to charge my 13" MBP and haven't really noticed anything bad happen yet. But I generally only do this when my 13" is sleeping or off.

However note that Apple does not advise mixing power adapters though, so if you do try out the other power adapter on the MBA, then you do so at your own risk.

Brains
30th March 2010, 11:21 PM
You can use your MBP's adaptor on the Air as long as the Air is switched off -- it'll be suitable for recharging, not during normal operation.

snark
31st March 2010, 06:02 AM
It's an extra 15watts over so I would say no. I may be wrong but I know when I had modem trouble I used other power bricks with different currents and they all stopped working. All 3 of them.

Perhaps they were supplying power at the wrong voltage, rather than the wrong current.

jho4evah
31st March 2010, 08:43 AM
Yeah it just stopped, nothing had happened to it. I'll just have to charge the Air with the Pro until the service centre at work gets a replacement for me. Thanks for the help!

~Coxy
31st March 2010, 11:19 AM
Most people are wrong about this. You can use the power brick just fine.
Wattage is the max amount that a device can draw upon, it's not a constant output rating and it won't fry your MBA.

When going the other way around, eg. using a 45W adaptor to power a MBP, is where you can run into usability issues. There it's better to use it to slowly charge the MBP while asleep or off.

Sebastianmonty
31st March 2010, 11:59 AM
Most people are wrong about this. You can use the power brick just fine.
Wattage is the max amount that a device can draw upon, it's not a constant output rating and it won't fry your MBA.

When going the other way around, eg. using a 45W adaptor to power a MBP, is where you can run into usability issues. There it's better to use it to slowly charge the MBP while asleep or off.
Well thanks for this info.
So basically we could all buy MBP chargers and be fine to charge all devices.

Sebastianmonty
31st March 2010, 12:00 PM
Perhaps they were supplying power at the wrong voltage, rather than the wrong current.

Don't know as I threw the dead weight out, but maybe.

Sebastianmonty
31st March 2010, 12:01 PM
You can use your MBP's adaptor on the Air as long as the Air is switched off -- it'll be suitable for recharging, not during normal operation.

Hey Brains why only when switched off? More recent posts suggest that it would be fine during normal operation as the computer will draw only want it needs.