This new battery features a capacity of 1440 mAh. That is up from the capacity of 1430 mAh on the iPhone 4S and up from 1420 mAh on the iPhone 4, according to iPhone repair shop iFixYouri, whom examined the battery photos.
Notably, the battery also features a new voltage of 3.8, up from 3.7 on the iPhone 4 and iPhone 4S.
The new battery also has an increased watts-per-hour measurement (wHr), 5.45 wHr, which is an increase from 5.25 and 5.3 on the iPhone 4 and iPhone 4S, respectively. This is a proportional increase due to the increase from 1430 to 1440 mAh.
The battery is marked as being produced in June of this year. Take a look at the photos below.