is it ok to use the other macbook power adapters with the mb air?

I think we are mixing terms here.

I believe the Macbook Air, Macbook and Macbook Pro power adapters are 45W, 60W and 85W respectively. The power adapters don't push power to the notebooks, the notebooks draw power from the power adapters, Consequently you can always use a higher wattage adapter.

The Macbook and Macbook Pro use different voltages but all the power adapters seem to be able to use each. The Macbook Pro uses 4.6A (amps) and the Macbook uses 3.65A and the Macbook Air 3.1A. Pushing to many amps to a device would ruin the unit, but it seems like this has been planned as you can mix and match all the magsafe adapters today and they all function properly.

I have read that the notebook knows whether it can draw enough power to recharge the battery or only enough to run the computer while it is on and that in the latter case it will charge the battery when the notebook turns off. Whether this is bad for the charger or the notebook is unclear, but since the notebooks seem to respond intelligently in those different situations I think that the apple engineers have planned accordingly. If you draw too much power from the airline adapter for example, the airline adapter will simply stop providing power temporarily and the light will go off for a moment.

I would not do it.... Look at the output of the brick, it's printed on the side.
I looked this morning at my spare MB brick and it's a higher voltage than the one of the MBA.

I used to use a MB brick with a MBP laptop, that was fine beause it was a lower voltage, it would just take longer to charge.

In our case now the voltage is higher and would do some damage I imagine.

actually, if you read and search, you should not use a lower voltage adapter with a higher voltage comp. using a standard macbook charger should work, and to the poster who used a macbook charger with a macbook pro, using the lower wattage charger with the macbook pro could damage the charger, or even cause a fire

If you read and search you CAN use a MacBook charger with a MacBook Pro. In fact, it is well known that you should do just that on airplanes for example, since the in-seat plug doesn't provide enough wattage for the MBP charger.

Now I would not use a higher voltage charger on a lower voltage machine...

I have heard differing opinions on this. Is there an answer from Apple. I have extra MB and MBP power supplies around and would like to make use of them if it doesn't harm the MBA.
Thanks

Partly right, partly wrong.

You really ought to learn about the relationship between voltage, current and power before offering explanations.

So what's the verdict? Can I use my MacBook Pro's power adapter? I'd like to use it while my Air is plugged into the desk. So it would sit on this all day long on those few days I am in the office...

Thanks,

George

i have since i got my mba (about a week). to no ill effect. i have also constantly mixed up my mba and mb chargers to no ill effect. it just affects charge time.

I tried it both ways. It does not seem to have harmed either book. The MBA charger just seems to maintain the charge on the MBP, not add to it.

I really hope that the next iteration of all the intel power adapters has the MBA connection. So much stronger and so much more out of the way. The plastic covering on the cable by my MBA magsafe connection is trying to separate regardless of how careful I am and it is only 7 months old.

Message was edited by: Rhyd

tele_player wrote:
Partly right, partly wrong.

You really ought to learn about the relationship between voltage, current and power before offering explanations.

What an unhelpful comment. If you know better why not share your knowledge? Sniping like this just makes you look like an armchair commentator.

Fair enough - bad day, and I probably was just misreading his second paragraph about 'pushing', so I also retract the whole thing.

Thanks everyone for the input. But I'm still a bit concerned. I would love to use the MBP and MB power adaptors but don't want to "fry" my MBA. Is there any word from Apple --or anyone else want to give the "official word?"

Thanks

It is safe to use 85W and 65W power adapters with the MacBook Air. It will not "over drive" the battery or circuitry.

Caveat: Though the statement above is based on a discussion with someone with expertise in electrical engineering and knowledge of Apple products, when I tried out an 85W adapter on our MacBook Air, it seemed to get warmer than when using the 45W adapter. Because that's a subjective opinion, I'm going to run further tests and actually measure the enclosure bottom using both a temperature probe and Hardware Monitor and report back to you.

What is interesting is when I used the MBP (80W) charger my MacBook Air charged up a lot faster than when using the provided one (45W). And one more note: unlike MB and MBP the power page in system profiler does not report the kind of power adapter connected.