Apple was obviously keen to talk up the many skills of the iPhone 6S last night, but one thing it didn't mention was battery power. However, it inadvertently let slip the details in its own video.
The promo video for the 6S features the battery clearly marked 1,715mAh. That's a slightly lower capacity than the 1,810mAh battery in the iPhone 6.
Despite this smaller battery, Apple claims the 6S will last just as long as its predecessor.
On paper that means it'll provide 14 hours of talk time on 3G, up to 10 hours internet use on 3G or LTE and 11 hours on Wi-Fi, 11 hours of HD video playback, 5 hours of audio playback and 10 days of standby time.
Apple doesn't provide details of the batteries used in its iPhones, but the numerous teardowns reveal all the details.
The A9 chip and iOS 9 should also make the 6S run more efficiently than the 6, so the smaller battery shouldn't make any difference to performance.
The 6S and 6S Plus feature Live Videos, which add a second and a half of animations either side of when you pressed the shutter to take a photo.
They both also have always-on Siri, so you can just say "Hey Siri" and it'll respond. You had to plug in previous iPhones to do so, or open the Siri app first.