At least for the MBA, it's common to see the system run hotter when plugged in and charging. After the battery is charged, the temperature should be the same regardless.
I noticed this on the 2009's 2.13GHz Intel Core 2 Duo MBA when I had it. It ran hotter on AC then Battery by quite a bit.
I noticed this on the 2009's 2.13GHz Intel Core 2 Duo MBA when I had it. It ran hotter on AC then Battery by quite a bit.