Enlarge/ The iPhone 6S and 6S Plus. (credit: Andrew Cunningham)
Apple has two companies manufacturing the A9 chip in its iPhone 6S and 6S Plus this year: Samsung and TSMC. Early tests from some users suggested that there were big differences in battery life between phones with different chips, though Apple's own data and our independent testing showed a smaller difference between the two for most real-world tasks. Now Consumer Reports is weighing in, and it's saying the same thing: there's "no appreciable difference" in battery life between iPhones with different A9 chips.
The publication ran two different tests, one that stressed cellular connectivity and one that continuously loads webpages while playing music. In both cases, the difference between the two phones was between one and two percent, the same margin that Apple provided. With the exception of the Geekbench test, our battery life tests showed roughly the same thing.
Consumer Reports controlled its tests in much the same way we did: it picked two iPhone 6Ses on the same carrier and made sure the software and screen brightness settings were all identical. While its tests have the same shortcomings as ours—a small sample size, inability to identify whether components like screens, RAM, and NAND all came from the same suppliers—they still suggest that the drastic differences initially reported are not representative of real-world use.