MBP and MBA Power Supply

[LenInSebastopol]

New to Mac and now have TWO.
MBP is from August, 2007 and SWMBO has a NEW Mac Book Air.
Simple question, are the power supplies both the same?
Can I switch and use either power suppl and not have it make a difference? Or do I need to mark them clearly so we won't dote in our old age and mess them up.
TIA,
=Len

 

[foxj66]

I think they are different I believe the air uses 45w and the pro is 60w or 85w

 

[Jaygray]

The Air is 45w.
The 13" MB & MBP models are 60w.
15" & larger are 85w.

That being said, they are somewhat interchangeable. The wattage is the capacity the charger is capable of putting out. It's not going to force out more current than the machine is accepting. But a 15" MBP on a 45w charger is going to charge very slowly.