7 plus is a lot better
“Documentation spotted from Chinese regulatory body TENAA reveals that the iPhone 7 has a 1,960 mAh battery, which is slightly bigger than the 1,715 mAh battery in the iPhone 6s. The iPhone 7 Plus has a 2,900 mAh battery, which is bigger than the iPhone 6s Plus’s 2,750 mAh battery as well.”