Yesterday’s iPad Air teardown by iFixit revealed that Apple’s latest 9.7” tablet now sports a 32.9 WHr, two-cell battery, which is smaller than the iPad 4’s 43 WHr, three-cell battery. Now we find that not only does the new battery help Apple build a 20% thinner and 28% lighter full-sized tablet, but also seems to last longer than the previous generation models, as evident from AnandTech’s latest finding that the iPad Air battery lasts 24 hours as LTE hotspot, due to its much lower platform power, thanks to Apple’s A7 SoC.
“I set the iPad Air up as a personal hotspot, wirelessly tethering it to a 13-inch MacBook Pro with Retina Display. I started a constant 100KB/s transfer on the MacBook Pro (2x the transfer rate of my iPad 3 test) and with the iPad Air’s display off I measured battery life. Last time I chose 50KB/s as it was the average transfer rate across our old WiFi web browsing battery life test, I doubled the workload to be more reflective of more strenuous demands. In reality I’d expect to see a burstier usage profile, but that’s something for me to test down the road.”
AnandTech was able to get a total of 24.08 hours and over 8GB of data transfer, before the iPad Air battery finally gave up.
The source highlights that the idle platform power requirement is substantially lower on the iPad Air as compared to the iPad 4. Furthermore, it details that the A7 SoC is built on Samsung’s 28nm LP process, while the A5X used in the iPad 3 was a 45nm part. Also, Qualcomm’s MDM9600 in the iPad 3 was also built on a 45nm process, compared to the 28nm process used on the MDM9615M, which is the same modem also found in iPhone 5S. So an improvement of two process nodes on both the SoC and modem must have a significant impact on battery life.