Galaxy Z Fold 8 Ultra battery tests reveal the biggest challenge facing the iPhone Duo

Samsung’s foldables have always leaned heavily on deep optimization to squeeze respectable endurance out of tight space constraints. With the Galaxy Z Fold 8 Ultra , Samsung finally adopted a dense 5,000mAh silicon-carbon (Si-C) cell, potentially marking a major turning point in foldable battery life. Shortly after, Apple finally announced its own take on booklet hardware with the iPhone Duo .