iPhone with the biggest battery yet is currently (officially) iPhone 11 Pro Max with its 3,968 mAh of capacity. Apple did not specified how big battery is in the iPhone 12 lineup. Why? Should we be worried about battery life? Maybe yes, because battery capacity is reportedly lower than in the iPhone 11 lineup. Infos about battery capacity was leaked by server tecnoblog.net. Regulatory filing from Brazil says that iPhone 12 mini only has a battery capacity of 2,227mAh. Bigger iPhone 12 should have a 2,815mAh battery. That’s lower than iPhone 11 with its 3,110 mAh battery.
This leak comes from ANATEL, Brazil’s National Telecommunications Agency that certifies new electronic devices. Though source claims it has battery capacity of all four iPhone 12 models, infos about battery capacity of iPhone 12 Pro and its Max brother were not shared.
Based on another leak, the iPhone 12 Pro Max should have a 3,687mAh battery, still smaller than in an iPhone 11 Pro Max. Though A14 Bionic is slighty more power efficient in compare to the A13 Bionic, iPhones 12 will probably have lower battery life per one charge.
Similar situation is with iPhone 8 and iPhone SE 2020. Though they have almost the same battery (and display, etc.), iPhone SE has slightly better battery life thanks to more efficient A13 Bionic chip in compare to A11 chip found in iPhone 8.
In the past, I had iPhone 6s with its 1715 mAh battery and over 90% of overal battery health and when I purchased iPhone SE 2020 with its 1821 mAh battery (but also 100% battery health due to new battery), battery life increased significantly. Every new chip from Apple is faster and more energy efficient, and because iPhone SE 2020 comes from iPhone 8 which comes from iPhone 6s, this is probably the reason why my current iPhone has much better battery life.