rMBP vs. MBA battery question?

[pk314]

Hey everyone,

So I recently purchased a 13in MBA 1.4/4gb/256gb and a 13in rMBP 2.4/8gb/256gb and I set up the rMBP first and used Time Machine to back it up and then went to the migration assistant on the Air and used that back up to load from. I charged both laptops to 100% and put both laptops to the same level of brightness. With all apps except, finder of course, closed on both laptops and just sitting idle on the desktop, the Air's expected battery time remaining at 99% shows 14:21, while the Pro's expected battery time remaining at 92% shows 16:38. What would account for this 2 hour difference? It is weird because the Air is supposed to be getting better battery life.

 

[phillyred79]

I don't have the answer, but I did a similar test with similar equipment and found that after about 10-15 min with both monitors still on and not going dark/standby the MBA jumped way ahead in duration left while the rMBP started to decline much faster. The MBA was still around 96% while the rMBP was already down to 85%. Very rarely have I ever found the actual time/% left calculated be true to what has been estimated.

 

[mfram]

13" MBA has 54 watt-hour battery. 13" rMBP has 71.8 watt-hour battery according to Apple Specs page.