How the iPad Air got thinner, lighter
The iPad 3 and 4 were relatively heavy because of compromises Apple had to make to accommodate the Retina Display. Here's how the Air tries to fix that problem.
The iPad 4 was a relatively hefty 1.44 pounds. The Air is an even 1 pound. So, how did Apple do it? A teardown and an analyst help explain.
As iFixit demonstrated in its teardown of the Air on Friday, the device's 33 WHr, two-cell battery is "decidedly less monstrous than the previous iPad's 43 WHr, three-cell behemoth."
The image above shows how the battery dominates the iPad's internal real estate. So cutting back on this one component's size and weight is a big factor in making the Air 28 percent lighter and 20 percent thinner overall.
But Apple took a "holistic approach" to weight loss, said Wayne Lam, an analyst at IHS iSuppli. That means Apple shed the aluminum chassis' bulk too.
"The new unibody construction and the smaller bezel indicates that the overall aluminum content is reduced, saving weight," Lam said.
A thinner, lighter display module also factored into trimming weight from the previous generation iPads, Lam said.
The Air uses less than half the light-emitting diodes (LED) to illuminate the liquid-crystal display (LCD) compared to the earlier-generation iPad, allowing the battery size to be reduced.
Finally, power-efficient electronics that deliver better performance with little or no increase in power consumption allow Apple to pack the slimmer Air with new components like the A7 processor.
"The updated A7 processor and supporting electronics draw less on the reduced-capacity battery. And likely design improvements to the display will draw less on the battery," according to Lam.
Which brings us back to iFixit's teardown. The Air uses a different version of the 64-bit A7, as indicated by the numbering on the chip.
But cramming all of the above into a thinner chassis has its downside too: iFixit gave the Air a repairability score of 2 out of 10, with 10 being the easiest to repair.
"Gobs, gobs, and goblins of adhesive hold everything in place. This is the most difficult battery removal procedure we've seen in an iPad," iFixit said.