There are a heap of rumors surrounding Apple's new iPhone 8 - which is meant to be joined by the higher-end, ground breaking iPhone X - but for now, we'll stick to the iPhone 8 discussion.
According to KGI Securities analyst Ming-Chi Kuo, Apple will be using a more expensive stacked logic board for the new iPhone 8 - which is also known as a "substrate-like PCB mainboard". The benefits? It'll see the iPhone 8 with an OLED display that will have a similar size to the 4.7-inch iPhone, but with battery life more akin to the larger 5.5-inch iPhone.
Kuo expects the 4.7-inch iPhone 8 to have a 2700Mah L-shaped two-cell battery pack, adding: "As battery material tech isn't likely to see major breakthroughs in the next 3-5 years, mainboard area can only be reduced via stacked SLP, which makes space for larger battery and extended usage time. Thanks to stacked SLP, we expect the OLED iPhone to have similar dimensions to a 4.7" TFT-LCD iPhone, and have comparable battery capacity (equipped with around 2,700 mAh L-shaped 2-cell battery pack) to a 5.5" TFT-LCD iPhone. The battery life of the OLED iPhone could be better than that of the 5.5" TFT-LCD model as OLED panels are more energy-efficient than their TFT-LCD counterparts".
Kuo teased that the OLED-based 4.7-inch iPhone 8 should have better battery life numbers than the bigger 5.5-inch iPhone 7 Plus, as OLED panels are more power efficient. Consindering the iPhone 7 has a 1960mAh battery and the bigger iPhone 7 Plus has a 2900mAh battery - these improvements are actually quite significant.