The 13 inch gets up to 12 hours with Intel i7 processor.

That is more than the 11 inch MBA which gets up to 9 hours.

Main reason is battery capacity, 38 vs 54 wh.

The larger SSD and more RAM have negligible power consumption.

For example: 4 Gig RAM consumes 4 watt, while 8 Gig Ram consumes 8 watt, but on the other hand the i7 CPU consumes up to 100 watt under heavy load.

Apple specifies 12 hours with i7 on 13 inch MBA.

Since the CPU and the LCD screen are the 2 larges power consumers it is safe to say that the 13 inch MBA with i7, 8G RAM and 512 G SSD will yield up to 12 hours on single battery charge.

The 13 inch MBA gets up to 12 hours with Intel i7 processor.

That is actualy more than the 11 inch MBA which gets up to 9 hours.

Main reason is battery capacity, 38 vs 54 watt hours.

The larger SSD and more RAM have negligible power consumption.

For example: 4 Gig RAM consumes 4 watt, while 8 Gig Ram consumes 8 watt, but on the other hand the i7 CPU consumes up to 100 watt under heavy load.

Apple specifies 12 hours with i7 on 13 inch MBA.

Since the CPU and the LCD screen are the 2 larges power consumers it is safe to say that the 13 inch MBA with i7, 8G RAM and 512 G SSD will yield up to 12 hours on single battery charge.

The 13 inch gets up to 12 hours with Intel i7 processor.

That is more than the 11 inch MBA which gets up to 9 hours.

Main reason is battery capacity, 38 vs 54 wh.

The larger SSD and more RAM have negligible power consumption.

Since the CPU and the LCD are the 2 larges power consumers it is safe to say that the 13 inch MBA with i7, 8G RAM and 512 G SSD will yield up to 12 hours on single battery charge.

The 13 inch gets up to 12 hours with Intel i7 processor.

That is more than the 11 inch MBA which gets up to 9 hours.

Main reason is battery capacity, 38 vs 54 wh.

The larger SSD and more RAM have negligible power consumption.

For example: 4 Gig RAM consumes 4 watt, while 8 Gig Ram consumes 8 watt, but on the other hand the i7 CPU consumes up to 100 watt under heavy load.

Apple specifies 12 hours with i7 on 13 inch MBA.

Since the CPU and the LCD screen are the 2 larges power consumers it is safe to say that the 13 inch MBA with i7, 8G RAM and 512 G SSD will yield up to 12 hours on single battery charge.