It turns out that the battery of iPhone 12 is 'same life' as iPhone 11 but 'capacity is small'

Is a Brazilian communication regulatory authorities ANATEL from documents, Apple is to launch on October 23, 2020 iPhone 12 and, the battery capacity of the iPhone 12 mini to be released on November 13, 2020 was found. According to the document, the battery of the iPhone 12 has almost the same life as the iPhone 11, but the capacity is less than the previous model.

iPhone 12 Pro é homologado na Anatel; iPhone 12 Mini tem bateria de 2.227 mAh | Celular | Tecnoblog
https://tecnoblog.net/375172/o-que-e-ceramic-shield-do-iphone-12/

iPhone 12 mini has 2,227 mAh battery, new models will likely be assembled in Brazil and India ―― 9to5Mac
https://9to5mac.com/2020/10/16/iphone-12-mini-battery-new-models-assembled-in-brazil-and-india/

Brazilian Certifications Suggest iPhone 12 Mini Features 2,227mAh Battery and iPhone 12 Has 2,815mAh Battery --MacRumors
https://www.macrumors.com/2020/10/16/iphone-12-12-mini-battery-capacity/

According to ANATEL, the battery built into the iPhone 12 is 2815mAh, which is about 10% less than the battery built into the iPhone 11 (3110mAh).

However, both iPhone 11 and iPhone 12 have official specifications for up to 17 hours of video playback time, with the same battery life. It is believed that this is because the chipset installed in the iPhone 12 has been upgraded to the A14 Bionic , which uses the 5nm process, which has greatly improved battery efficiency.

Also, the battery used in the iPhone 12 mini is called 'A2471' and has a capacity of 2227mAh. Compared to the 1821mAh battery used in the second-generation iPhone SE , which is about the same size, the capacity has increased by 22%.

Apple's nominal battery for the iPhone 12 mini can play up to 15 hours of video. The battery life of the 2nd generation iPhone SE is up to 13 hours when playing video, so it seems that the battery life is of course longer as the capacity increases.

According to ANATEL documents, the iPhone 12 and iPhone 12 mini are manufactured at Foxconn's assembly plants in Brazil and India, not in China. As of April 2019, it is clear that Foxconn has already started production of iPhone in India.

Foxconn, which manufactures iPhone, announces that it will start manufacturing iPhone in India --GIGAZINE