Apple promised improved battery life for its new iPhone 5s and 5c, but other than endurance times for a few use cases, the company gave little info on the battery itself. Luckily, it's FCC's job to certify such aspects of a mobile device so now we have the actual battery capacity. The iPhone 5, 5s and 5c batteries all work at 3.8V, but differ in battery size. The iPhone 5 had a 5.45Wh battery...
Source: http://www.gsmarena.com/the_iphone_5c_and_5s_have_bigger_batteries_than_the_iphone_5-news-6784.php
