iPad Air has 31% smaller battery, yet same great battery life18
The dramatically reduced size and thickness are among the many factors making the iPad Air so much better than the previous model. As a matter of fact, the fifth-generation iPad is the lightest full-size tablet in the world, as Apple itself stated during the device's official announcement. And achieving this goal has not been an easy task. Apple had to shave off precious micrometers from a number of components that go into the iPad Air, including its screen, its shell, and its built-in rechargeable battery. The latter, in particular, is 25% thinner. This, however, has led to a decrease in battery capacity. While the iPad 4 had a 42.5Wh battery, the cell inside the iPad Air can hold no more than 32.4Wh of charge – a 31% difference.
Yet despite all that, the iPad Air can still last through 10 hours of active use, just like its predecessor. Or as Apple claims, its tablet can deliver 10 hours of web browsing on Wi-Fi or continuous video playback. How is that possible? Well, it all comes down to the overall efficiency of Apple's tablet – the efficiency of its hardware and the software controlling it, to be more specific. The new Apple A7 chip, despite being more powerful than the 32nm A6X used in the iPad 4, is more energy efficient, being built using 28-nm technology. Also, we wouldn't be surprised if the Retina display has been made less power-hungry, although this has yet to be confirmed.
The moral of the story is that a bigger battery does not necessarily guarantee better battery life, as much as we love to compare the milliamp-hour capacity of cells used in phones and tablets. Clearly, the power efficiency of their hardware plays a key role as well, so think about that next time you marvel at the specs sheet of any company's latest flagship.