The new battery is a significant increase compared to the previous 1560 mAh for the iPhone 5S.
A photo that leaked online last month showed a 1,810 mAh battery allegedly assigned to the 4.7-inch iPhone.
Sung Chang Xu claims the respective unit was only meant for testing purposes.
Xu is the same analyst who claimed that the highly-anticipated smartphone will be equipped with temperature, pressure and humidity sensors, as well as electronic image stabilization.
Various websites have reported that Cupertino has had to deal with manufacturing issues with the battery destined for the ultra-thin iPhone 6 but those problems have reportedly been solved with the help of new suppliers.
Recent rumors suggest that the next iPhone models will be unveiled at a September 9th media event by Apple.