It turns out the rumors were true—battery capacity is down a bit, likely in order to make room for new features like the Taptic Engine and slightly thicker display.
This iPhone's battery still has the same identity issues as last year's. It seems to think it's from Apple South Asia (Thailand) Limited, Apple Japan, and is made in Changsu, China.
Nevertheless, Apple says battery life holds steady at up to 14 hours of 3G talk time and 10 days of standby—the same as in the iPhone 6. A lot of this is likely due to more efficient silicon, which we're eager to get a look at...